WorldWideScience

Sample records for bootstrap model search

  1. Bootstrapping heteroskedastic regression models: wild bootstrap vs. pairs bootstrap

    OpenAIRE

    Flachaire, Emmanuel

    2005-01-01

    International audience In regression models, appropriate bootstrap methods for inference robust to heteroskedasticity of unknown form are the wild bootstrap and the pairs bootstrap. The finite sample performance of a heteroskedastic-robust test is investigated with Monte Carlo experiments. The simulation results suggest that one specific version of the wild bootstrap outperforms the other versions of the wild bootstrap and of the pairs bootstrap. It is the only one for which the bootstrap ...

  2. Bootstrap and Wild Bootstrap for High Dimensional Linear Models

    OpenAIRE

    Mammen, Enno

    1993-01-01

    In this paper two bootstrap procedures are considered for the estimation of the distribution of linear contrasts and of F-test statistics in high dimensional linear models. An asymptotic approach will be chosen where the dimension p of the model may increase for sample size $n\\rightarrow\\infty$. The range of validity will be compared for the normal approximation and for the bootstrap procedures. Furthermore, it will be argued that the rates of convergence are different for the bootstrap proce...

  3. Unsupervised model compression for multilayer bootstrap networks

    OpenAIRE

    ZHANG, XIAO-LEI

    2015-01-01

    Recently, multilayer bootstrap network (MBN) has demonstrated promising performance in unsupervised dimensionality reduction. It can learn compact representations in standard data sets, i.e. MNIST and RCV1. However, as a bootstrap method, the prediction complexity of MBN is high. In this paper, we propose an unsupervised model compression framework for this general problem of unsupervised bootstrap methods. The framework compresses a large unsupervised bootstrap model into a small model by ta...

  4. Statistical bootstrap model and annihilations

    CERN Document Server

    Möhring, H J

    1974-01-01

    The statistical bootstrap model (SBM) describes the decay of single, high mass, hadronic states (fireballs, clusters) into stable particles. Coupling constants B, one for each isospin multiplet of stable particles, are the only free parameter of the model. They are related to the maximum temperature parameter T/sub 0/. The various versions of the SMB can be classified into two groups: full statistical bootstrap models and linear ones. The main results of the model are the following: i) All momentum spectra are isotropic; especially the exclusive ones are described by invariant phase space. The inclusive and semi-inclusive single-particle distributions are asymptotically of pure exponential shape; the slope is governed by T /sub 0/ only. ii) The model parameter B for pions has been obtained by fitting the multiplicity distribution in pp and pn at rest, and corresponds to T/sub 0/=0.167 GeV in the full SBM with exotics. The average pi /sup -/ multiplicity for the linear and the full SBM (both with exotics) is c...

  5. A new approach to bootstrap inference in functional coefficient models

    OpenAIRE

    Herwartz, Helmut; Xu, Fang

    2007-01-01

    We introduce a new, factor based bootstrap approach which is robust under heteroskedastic error terms for inference in functional coefficient models. Modeling the functional coefficient parametrically, the bootstrap approximation of an F statistic is shown to hold asymptotically. In simulation studies with both parametric and nonparametric functional coefficients, factor based bootstrap inference outperforms the wild bootstrap and pairs bootstrap approach according to its size features. Apply...

  6. Maximum Likelihood and the Bootstrap for Nonlinear Dynamic Models

    OpenAIRE

    Goncalves, Silvia; White, Halbert

    2002-01-01

    The bootstrap is an increasingly popular method for performing statistical inference. This paper provides the theoretical foundation for using the bootstrap as a valid tool of inference for quasi-maximum likelihood estimators (QMLE). We provide a unified framework for analyzing bootstrapped extremum estimators of nonlinear dynamic models for heterogeneous dependent stochastic processes. We apply our results to two block bootstrap methods, the moving blocks bootstrap of Künsch (1989) and Liu a...

  7. Bootstrapped models for intrinsic random functions

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, K.

    1988-08-01

    Use of intrinsic random function stochastic models as a basis for estimation in geostatistical work requires the identification of the generalized covariance function of the underlying process. The fact that this function has to be estimated from data introduces an additional source of error into predictions based on the model. This paper develops the sample reuse procedure called the bootstrap in the context of intrinsic random functions to obtain realistic estimates of these errors. Simulation results support the conclusion that bootstrap distributions of functionals of the process, as well as their kriging variance, provide a reasonable picture of variability introduced by imperfect estimation of the generalized covariance function.

  8. Bootstrapped models for intrinsic random functions

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, K.

    1987-01-01

    The use of intrinsic random function stochastic models as a basis for estimation in geostatistical work requires the identification of the generalized covariance function of the underlying process, and the fact that this function has to be estimated from the data introduces an additional source of error into predictions based on the model. This paper develops the sample reuse procedure called the ''bootstrap'' in the context of intrinsic random functions to obtain realistic estimates of these errors. Simulation results support the conclusion that bootstrap distributions of functionals of the process, as well as of their ''kriging variance,'' provide a reasonable picture of the variability introduced by imperfect estimation of the generalized covariance function.

  9. Non-Parametric Data Dependent Bootstrap for Conditional Moment Model

    OpenAIRE

    Bruce E. Hansen

    2000-01-01

    A new non-parametric bootstrap is introduced for dependent data. The bootstrap is based on a weighted empirical-likelihood estimate of the one-step-ahead conditional distribution, imposing the conditional moment restrictions implied by the model. This is the first dependent-data bootstrap procedure which imposes conditional moment restrictions on a bootstrap distribution. The method can be applied to form confidence intervals and p-values from hypothesis tests in Generalized Method of Moments...

  10. Model Based Bootstrap Methods for Interval Censored Data

    OpenAIRE

    Sen, Bodhisattva; Xu, Gongjun

    2013-01-01

    We investigate the performance of model based bootstrap methods for constructing point-wise confidence intervals around the survival function with interval censored data. We show that bootstrapping from the nonparametric maximum likelihood estimator of the survival function is inconsistent for both the current status and case 2 interval censoring models. A model based smoothed bootstrap procedure is proposed and shown to be consistent. In addition, simulation studies are conducted to illustra...

  11. Bootstrap determination of the cointegration rank in heteroskedastic VAR models

    DEFF Research Database (Denmark)

    Cavaliere, Guiseppe; Rahbæk, Anders; Taylor, A.M. Robert

    2014-01-01

    In a recent paper Cavaliere et al. (2012) develop bootstrap implementations of the (pseudo-) likelihood ratio (PLR) co-integration rank test and associated sequential rank determination procedure of Johansen (1996). The bootstrap samples are constructed using the restricted parameter estimates of...... the underlying vector autoregressive (VAR) model which obtain under the reduced rank null hypothesis. They propose methods based on an independent and individual distributed (i.i.d.) bootstrap resampling scheme and establish the validity of their proposed bootstrap procedures in the context of a co......-integrated VAR model with i.i.d. innovations. In this paper we investigate the properties of their bootstrap procedures, together with analogous procedures based on a wild bootstrap resampling scheme, when time-varying behavior is present in either the conditional or unconditional variance of the innovations. We...

  12. The wild bootstrap for multilevel models

    OpenAIRE

    Modugno, Lucia; Giannerini, Simone

    2015-01-01

    In this paper we study the performance of the most popular bootstrap schemes for multilevel data. Also, we propose a modified version of the wild bootstrap procedure for hierarchical data structures. The wild bootstrap does not require homoscedasticity or assumptions on the distribution of the error processes. Hence, it is a valuable tool for robust inference in a multilevel framework. We assess the finite size performances of the schemes through a Monte Carlo study. The results show that for...

  13. A model study in hadron statistical bootstrap

    CERN Document Server

    Hagedorn, Rolf

    1973-01-01

    In the framework of the statistical bootstrap the decay of a fireball is considered as an exact inverse of its statistical composition. This assumption leads to a bootstrap formulated in terms of integral equations for all kinds of distributions of the fireball's decay products. Solutions of the equations are obtained in terms of power series and of K-transforms and determine in the general case their asymptotic behaviour for large fireball mass. Relations to a thermodynamical description are established and illustrated by effective temperatures. The approach to the asymptotic limits is easy to investigate in a simplified linear bootstrap where the K-transforms can be more explicitly calculated. (30 refs).

  14. Bootstrap inference longitudinal semiparametric regression model

    Science.gov (United States)

    Pane, Rahmawati; Otok, Bambang Widjanarko; Zain, Ismaini; Budiantara, I. Nyoman

    2016-02-01

    Semiparametric regression contains two components, i.e. parametric and nonparametric component. Semiparametric regression model is represented by yt i=μ (x˜'ti,zt i)+εt i where μ (x˜'ti,zt i)=x˜'tiβ ˜+g (zt i) and yti is response variable. It is assumed to have a linear relationship with the predictor variables x˜'ti=(x1 i 1,x2 i 2,…,xT i r) . Random error εti, i = 1, …, n, t = 1, …, T is normally distributed with zero mean and variance σ2 and g(zti) is a nonparametric component. The results of this study showed that the PLS approach on longitudinal semiparametric regression models obtain estimators β˜^t=[X'H(λ)X]-1X'H(λ )y ˜ and g˜^λ(z )=M (λ )y ˜ . The result also show that bootstrap was valid on longitudinal semiparametric regression model with g^λ(b )(z ) as nonparametric component estimator.

  15. Bootstrap tests in linear models with many regressors

    OpenAIRE

    Patrick Richard

    2014-01-01

    This paper is concerned with bootstrap hypothesis testing in high dimensional linear regression models. Using a theoretical framework recently introduced by Anatolyev (2012), we show that bootstrap F, LR and LM tests are asymptotically valid even when the numbers of estimated parameters and tested restrictions are not asymptotically negligible fractions of the sample size. These results are derived for models with iid error terms, but Monte Carlo evidence suggests that they extend to the wild...

  16. No unitary bootstrap for the fractal Ising model

    CERN Document Server

    Golden, John

    2015-01-01

    We consider the conformal bootstrap for spacetime dimension $1models, in particular with resummed $\\epsilon$-expansion and Monte Carlo simulations of the Ising model on fractal lattices. The bounds clearly rule out that these models correspond to unitary conformal field theories. We also clarify the $d\\to 1$ limit of the conformal bootstrap, showing that bounds can be - and indeed are - discontinuous in this limit. This discontinuity implies that for small $\\epsilon=d-1$ the expected critical exponents for the Ising model are disallowed, and in particular those of the $d-1$ expansion. Altogether these results strongly suggest that the Ising model universality class cannot be described by a unitary CFT below $d=2$. We argue this also from a bootstrap perspective, by showing that the $2\\leq d<4$ Ising "kink" splits into two features which grow apart below $d=2$.

  17. Bootstrapping Critical Ising Model on Three Dimensional Real Projective Space

    Science.gov (United States)

    Nakayama, Yu

    2016-04-01

    Given conformal data on a flat Euclidean space, we use crosscap conformal bootstrap equations to numerically solve the Lee-Yang model as well as the critical Ising model on a three dimensional real projective space. We check the rapid convergence of our bootstrap program in two dimensions from the exact solutions available. Based on the comparison, we estimate that our systematic error on the numerically solved one-point functions of the critical Ising model on a three dimensional real projective space is less than 1%. Our method opens up a novel way to solve conformal field theories on nontrivial geometries.

  18. Automatic bootstrapping of a morphable face model using multiple components

    NARCIS (Netherlands)

    Haar, F.B. ter; Veltkamp, R.C.

    2009-01-01

    We present a new bootstrapping algorithm to automatically enhance a 3D morphable face model with new face data. Our algorithm is based on a morphable model fitting method that uses a set of predefined face components. This fitting method produces accurate model fits to 3D face data with noise and ho

  19. More on analytic bootstrap for O(N) models

    CERN Document Server

    Dey, Parijat; Sen, Kallol

    2016-01-01

    This note is an extension of a recent work on the analytical bootstrapping of $O(N)$ models. An additonal feature of the $O(N)$ model is that the OPE contains trace and antisymmetric operators apart from the symmetric-traceless objects appearing in the OPE of the singlet sector. This in addition to the stress tensor $(T_{\\mu\

  20. A Bootstrap Cointegration Rank Test for Panels of VAR Models

    DEFF Research Database (Denmark)

    Callot, Laurent

    functions of the individual Cointegrated VARs (CVAR) models. A bootstrap based procedure is used to compute empirical distributions of the trace test statistics for these individual models. From these empirical distributions two panel trace test statistics are constructed. The satisfying small sample...

  1. A Bootstrap Cointegration Rank Test for Panels of VAR Models

    OpenAIRE

    Callot, Laurent

    2010-01-01

    This paper proposes a sequential procedure to determine the common cointegration rank of panels of cointegrated VARs. It shows how a panel of cointegrated VARs can be transformed in a set of independent individual models. The likelihood function of the transformed panel is the sum of the likelihood functions of the individual Cointegrated VARs (CVAR) models. A bootstrap based procedure is used to compute empirical distributions of the trace test statistics for these individual models. From th...

  2. BOOTSTRAP WAVELET IN THE NONPARAMETRIC REGRESSION MODEL WITH WEAKLY DEPENDENT PROCESSES

    Institute of Scientific and Technical Information of China (English)

    林路; 张润楚

    2004-01-01

    This paper introduces a method of bootstrap wavelet estimation in a nonparametric regression model with weakly dependent processes for both fixed and random designs. The asymptotic bounds for the bias and variance of the bootstrap wavelet estimators are given in the fixed design model. The conditional normality for a modified version of the bootstrap wavelet estimators is obtained in the fixed model. The consistency for the bootstrap wavelet estimator is also proved in the random design model. These results show that the bootstrap wavelet method is valid for the model with weakly dependent processes.

  3. Bootstrap Hypothesis Testing

    OpenAIRE

    MacKinnon, James G.

    2007-01-01

    This paper surveys bootstrap and Monte Carlo methods for testing hypotheses in econometrics. Several different ways of computing bootstrap P values are discussed, including the double bootstrap and the fast double bootstrap. It is emphasized that there are many different procedures for generating bootstrap samples for regression models and other types of model. As an illustration, a simulation experiment examines the performance of several methods of bootstrapping the supF test for structural...

  4. Bootstrap Determination of the Co-Integration Rank in Heteroskedastic VAR Models

    DEFF Research Database (Denmark)

    Cavaliere, Giuseppe; Rahbek, Anders; Taylor, A. M. Robert

    In a recent paper Cavaliere et al. (2012) develop bootstrap implementations of the (pseudo-) likelihood ratio [PLR] co-integration rank test and associated sequential rank determination procedure of Johansen (1996). The bootstrap samples are constructed using the restricted parameter estimates of...... the underlying VAR model which obtain under the reduced rank null hypothesis. They propose methods based on an i.i.d. bootstrap re-sampling scheme and establish the validity of their proposed bootstrap procedures in the context of a co-integrated VAR model with i.i.d. innovations. In this paper we...... investigate the properties of their bootstrap procedures, together with analogous procedures based on a wild bootstrap re-sampling scheme, when time-varying behaviour is present in either the conditional or unconditional variance of the innovations. We show that the bootstrap PLR tests are asymptotically...

  5. Bootstrap Determination of the Co-integration Rank in Heteroskedastic VAR Models

    DEFF Research Database (Denmark)

    Cavaliere, Giuseppe; Rahbek, Anders; Taylor, A.M.Robert

    In a recent paper Cavaliere et al. (2012) develop bootstrap implementations of the (pseudo-) likelihood ratio [PLR] co-integration rank test and associated sequential rank determination procedure of Johansen (1996). The bootstrap samples are constructed using the restricted parameter estimates of...... the underlying VAR model which obtain under the reduced rank null hypothesis. They propose methods based on an i.i.d. bootstrap re-sampling scheme and establish the validity of their proposed bootstrap procedures in the context of a co-integrated VAR model with i.i.d. innovations. In this paper we...... investigate the properties of their bootstrap procedures, together with analogous procedures based on a wild bootstrap re-sampling scheme, when time-varying behaviour is present in either the conditional or unconditional variance of the innovations. We show that the bootstrap PLR tests are asymptotically...

  6. A Parsimonious Bootstrap Method to Model Natural Inflow Energy Series

    Directory of Open Access Journals (Sweden)

    Fernando Luiz Cyrino Oliveira

    2014-01-01

    Full Text Available The Brazilian energy generation and transmission system is quite peculiar in its dimension and characteristics. As such, it can be considered unique in the world. It is a high dimension hydrothermal system with huge participation of hydro plants. Such strong dependency on hydrological regimes implies uncertainties related to the energetic planning, requiring adequate modeling of the hydrological time series. This is carried out via stochastic simulations of monthly inflow series using the family of Periodic Autoregressive models, PAR(p, one for each period (month of the year. In this paper it is shown the problems in fitting these models by the current system, particularly the identification of the autoregressive order “p” and the corresponding parameter estimation. It is followed by a proposal of a new approach to set both the model order and the parameters estimation of the PAR(p models, using a nonparametric computational technique, known as Bootstrap. This technique allows the estimation of reliable confidence intervals for the model parameters. The obtained results using the Parsimonious Bootstrap Method of Moments (PBMOM produced not only more parsimonious model orders but also adherent stochastic scenarios and, in the long range, lead to a better use of water resources in the energy operation planning.

  7. An SAS Macro for Implementing the Modified Bollen-Stine Bootstrap for Missing Data: Implementing the Bootstrap Using Existing Structural Equation Modeling Software

    Science.gov (United States)

    Enders, Craig K.

    2005-01-01

    The Bollen-Stine bootstrap can be used to correct for standard error and fit statistic bias that occurs in structural equation modeling (SEM) applications due to nonnormal data. The purpose of this article is to demonstrate the use of a custom SAS macro program that can be used to implement the Bollen-Stine bootstrap with existing SEM software.…

  8. Bootstrapping and Bartlett corrections in the cointegrated VAR model

    NARCIS (Netherlands)

    P.H. Omtzigt; S. Fachin

    2003-01-01

    The small sample properties of tests on long-run coefficients in cointegrated systems are still a matter of concern to applied econometricians. We compare the performance of the Bartlett correction, the bootstrap and the fast double bootstrap for tests on ccointegration parameters in the maximum lik

  9. Bootstrapping and Bartlett corrections in the cointegrated VAR model

    OpenAIRE

    Omtzigt, P.H.; Fachin, S.

    2002-01-01

    The small sample properties of tests on long-run coefficients in cointegrated systems are still a matter of concern to applied econometricians. We compare the performance of the Bartlett correction, the bootstrap and the fast double bootstrap for tests on ccointegration parameters in the maximum likelihood framework. We show by means of a theoretical result and simulations that all three procedures should be based on the unrestricted estimate of the cointegration vectors. The fast double boot...

  10. More on analytic bootstrap for O( N) models

    Science.gov (United States)

    Dey, Parijat; Kaviraj, Apratim; Sen, Kallol

    2016-06-01

    This note is an extension of a recent work on the analytical bootstrapping of O( N) models. An additonal feature of the O( N) model is that the OPE contains trace and antisymmetric operators apart from the symmetric-traceless objects appearing in the OPE of the singlet sector. This in addition to the stress tensor ( T μν ) and the ϕ i ϕ i scalar, we also have other minimal twist operators as the spin-1 current J μ and the symmetric-traceless scalar in the case of O( N). We determine the effect of these additional objects on the anomalous dimensions of the corresponding trace, symmetric-traceless and antisymmetric operators in the large spin sector of the O( N) model, in the limit when the spin is much larger than the twist. As an observation, we also verified that the leading order results for the large spin sector from the ɛ-expansion are an exact match with our n = 0 case. A plausible holographic setup for the special case when N = 2 is also mentioned which mimics the calculation in the CFT.

  11. Bootstrap Methods in Econometrics

    OpenAIRE

    MacKinnon, James G.

    2006-01-01

    There are many bootstrap methods that can be used for econometric analysis. In certain circumstances, such as regression models with independent and identically distributed error terms, appropriately chosen bootstrap methods generally work very well. However, there are many other cases, such as regression models with dependent errors, in which bootstrap methods do not always work well. This paper discusses a large number of bootstrap methods that can be useful in econometrics. Applications to...

  12. Bootstrap in Econometrics

    OpenAIRE

    Mitterpach, Róbert

    2012-01-01

    Aim of this thesis is to introduce the reader to the basic bootstrap techniques used in econometrics, to present their variations and importance. Results of the ordinary least squares model, residual bootstrap and case resampling bootstrap will be presented and compared on cross-sectional data and time series from small numbered random subsample from the available data. Bootstrap was shown to improve numerical performance of ordinary least squares model.

  13. A bootstrap based space-time surveillance model with an application to crime occurrences

    Science.gov (United States)

    Kim, Youngho; O'Kelly, Morton

    2008-06-01

    This study proposes a bootstrap-based space-time surveillance model. Designed to find emerging hotspots in near-real time, the bootstrap based model is characterized by its use of past occurrence information and bootstrap permutations. Many existing space-time surveillance methods, using population at risk data to generate expected values, have resulting hotspots bounded by administrative area units and are of limited use for near-real time applications because of the population data needed. However, this study generates expected values for local hotspots from past occurrences rather than population at risk. Also, bootstrap permutations of previous occurrences are used for significant tests. Consequently, the bootstrap-based model, without the requirement of population at risk data, (1) is free from administrative area restriction, (2) enables more frequent surveillance for continuously updated registry database, and (3) is readily applicable to criminology and epidemiology surveillance. The bootstrap-based model performs better for space-time surveillance than the space-time scan statistic. This is shown by means of simulations and an application to residential crime occurrences in Columbus, OH, year 2000.

  14. Bootstrap, Wild Bootstrap and Generalized Bootstrap

    OpenAIRE

    Mammen, Enno

    1995-01-01

    Some modifications and generalizations of the bootstrap procedurehave been proposed. In this note we will consider the wild bootstrap and the generalized bootstrap and we will give two arguments why it makes sense touse these modifications instead of the original bootstrap. The firstargument is that there exist examples where generalized and wild bootstrapwork, but where the original bootstrap fails and breaks down. The secondargument will be based on higher order considerations. We will show...

  15. Urban water demand forecasting and uncertainty assessment using ensemble wavelet-bootstrap-neural network models

    Science.gov (United States)

    Tiwari, Mukesh K.; Adamowski, Jan

    2013-10-01

    A new hybrid wavelet-bootstrap-neural network (WBNN) model is proposed in this study for short term (1, 3, and 5 day; 1 and 2 week; and 1 and 2 month) urban water demand forecasting. The new method was tested using data from the city of Montreal in Canada. The performance of the WBNN method was compared with the autoregressive integrated moving average (ARIMA) and autoregressive integrated moving average model with exogenous input variables (ARIMAX), traditional NNs, wavelet analysis-based NNs (WNN), bootstrap-based NNs (BNN), and a simple naïve persistence index model. The WBNN model was developed as an ensemble of several NNs built using bootstrap resamples of wavelet subtime series instead of raw data sets. The results demonstrated that the hybrid WBNN and WNN models produced significantly more accurate forecasting results than the traditional NN, BNN, ARIMA, and ARIMAX models. It was also found that the WBNN model reduces the uncertainty associated with the forecasts, and the performance of WBNN forecasted confidence bands was found to be more accurate and reliable than BNN forecasted confidence bands. It was found in this study that maximum temperature and total precipitation improved the accuracy of water demand forecasts using wavelet analysis. The performance of WBNN models was also compared for different numbers of bootstrap resamples (i.e., 25, 50, 100, 200, and 500) and it was found that WBNN models produced optimum results with different numbers of bootstrap resamples for different lead time forecasts with considerable variability.

  16. Asymptotic refinements of bootstrap tests in a linear regression model ; A CHM bootstrap using the first four moments of the residuals

    OpenAIRE

    Treyens, Pierre-Eric

    2008-01-01

    We consider linear regression models and we suppose that disturbances are either Gaussian or non Gaussian. Then, by using Edgeworth expansions, we compute the exact errors in the rejection probability (ERPs) for all one-restriction tests (asymptotic and bootstrap) which can occur in these linear models. More precisely, we show that the ERP is the same for the asymptotic test as for the classical parametric bootstrap test it is based on as soon as the third cumulant is nonnul. On the other sid...

  17. Bootstrapping critical Ising model on three-dimensional real projective space

    CERN Document Server

    Nakayama, Yu

    2016-01-01

    Given a conformal data on a flat Euclidean space, we use crosscap conformal bootstrap equations to numerically solve the Lee-Yang model as well as the critical Ising model on a three-dimensional real projective space. We check the rapid convergence of our bootstrap program in two-dimensions from the exact solutions available. Based on the comparison, we estimate that our systematic error on the numerically solved one-point functions of the critical Ising model on a three-dimensional real projective space is less than one percent. Our method opens up a novel way to solve conformal field theories on non-trivial geometries.

  18. Bootstrapping Mixed Correlators in the 3D Ising Model

    CERN Document Server

    Kos, Filip; Simmons-Duffin, David

    2014-01-01

    We study the conformal bootstrap for systems of correlators involving non-identical operators. The constraints of crossing symmetry and unitarity for such mixed correlators can be phrased in the language of semidefinite programming. We apply this formalism to the simplest system of mixed correlators in 3D CFTs with a $\\mathbb{Z}_2$ global symmetry. For the leading $\\mathbb{Z}_2$-odd operator $\\sigma$ and $\\mathbb{Z}_2$-even operator $\\epsilon$, we obtain numerical constraints on the allowed dimensions $(\\Delta_\\sigma, \\Delta_\\epsilon)$ assuming that $\\sigma$ and $\\epsilon$ are the only relevant scalars in the theory. These constraints yield a small closed region in $(\\Delta_\\sigma, \\Delta_\\epsilon)$ space compatible with the known values in the 3D Ising CFT.

  19. Parametric bootstrap methods for testing multiplicative terms in GGE and AMMI models.

    Science.gov (United States)

    Forkman, Johannes; Piepho, Hans-Peter

    2014-09-01

    The genotype main effects and genotype-by-environment interaction effects (GGE) model and the additive main effects and multiplicative interaction (AMMI) model are two common models for analysis of genotype-by-environment data. These models are frequently used by agronomists, plant breeders, geneticists and statisticians for analysis of multi-environment trials. In such trials, a set of genotypes, for example, crop cultivars, are compared across a range of environments, for example, locations. The GGE and AMMI models use singular value decomposition to partition genotype-by-environment interaction into an ordered sum of multiplicative terms. This article deals with the problem of testing the significance of these multiplicative terms in order to decide how many terms to retain in the final model. We propose parametric bootstrap methods for this problem. Models with fixed main effects, fixed multiplicative terms and random normally distributed errors are considered. Two methods are derived: a full and a simple parametric bootstrap method. These are compared with the alternatives of using approximate F-tests and cross-validation. In a simulation study based on four multi-environment trials, both bootstrap methods performed well with regard to Type I error rate and power. The simple parametric bootstrap method is particularly easy to use, since it only involves repeated sampling of standard normally distributed values. This method is recommended for selecting the number of multiplicative terms in GGE and AMMI models. The proposed methods can also be used for testing components in principal component analysis.

  20. Bootstrap planning: Theory and application

    Energy Technology Data Exchange (ETDEWEB)

    Chen, P.C.

    1994-02-01

    We identify a general framework for weak planning called bootstrap planning, which is defined as global planning using only a local planner along with some memory for learning intermediate subgoals. We present a family of algorithms for bootstrap planning, and provide some initial theory on their performance. In our theoretical analysis, we develop a random digraph problem model and use it to make some performance predictions and comparisons of these algorithms. We also use it to provide some techniques for approximating the optimal resource bound on the local planner to achieve the best global planner. We validate our theoretical results with empirical demonstration on the 15-puzzle. We show how to reduce the planning cost of a global planner by 2 orders of magnitude using bootstrap planning. We also demonstrate a natural but not widely recognized connection between search costs and the lognormal distribution.

  1. Comparison of cross-validation and bootstrap aggregating for building a seasonal streamflow forecast model

    Science.gov (United States)

    Schick, Simon; Rössler, Ole; Weingartner, Rolf

    2016-10-01

    Based on a hindcast experiment for the period 1982-2013 in 66 sub-catchments of the Swiss Rhine, the present study compares two approaches of building a regression model for seasonal streamflow forecasting. The first approach selects a single "best guess" model, which is tested by leave-one-out cross-validation. The second approach implements the idea of bootstrap aggregating, where bootstrap replicates are employed to select several models, and out-of-bag predictions provide model testing. The target value is mean streamflow for durations of 30, 60 and 90 days, starting with the 1st and 16th day of every month. Compared to the best guess model, bootstrap aggregating reduces the mean squared error of the streamflow forecast by seven percent on average. Thus, if resampling is anyway part of the model building procedure, bootstrap aggregating seems to be a useful strategy in statistical seasonal streamflow forecasting. Since the improved accuracy comes at the cost of a less interpretable model, the approach might be best suited for pure prediction tasks, e.g. as in operational applications.

  2. The economics of bootstrapping space industries - Development of an analytic computer model

    Science.gov (United States)

    Goldberg, A. H.; Criswell, D. R.

    1982-01-01

    A simple economic model of 'bootstrapping' industrial growth in space and on the Moon is presented. An initial space manufacturing facility (SMF) is assumed to consume lunar materials to enlarge the productive capacity in space. After reaching a predetermined throughput, the enlarged SMF is devoted to products which generate revenue continuously in proportion to the accumulated output mass (such as space solar power stations). Present discounted value and physical estimates for the general factors of production (transport, capital efficiency, labor, etc.) are combined to explore optimum growth in terms of maximized discounted revenues. It is found that 'bootstrapping' reduces the fractional cost to a space industry of transport off-Earth, permits more efficient use of a given transport fleet. It is concluded that more attention should be given to structuring 'bootstrapping' scenarios in which 'learning while doing' can be more fully incorporated in program analysis.

  3. The use of vector bootstrapping to improve variable selection precision in Lasso models.

    Science.gov (United States)

    Laurin, Charles; Boomsma, Dorret; Lubke, Gitta

    2016-08-01

    The Lasso is a shrinkage regression method that is widely used for variable selection in statistical genetics. Commonly, K-fold cross-validation is used to fit a Lasso model. This is sometimes followed by using bootstrap confidence intervals to improve precision in the resulting variable selections. Nesting cross-validation within bootstrapping could provide further improvements in precision, but this has not been investigated systematically. We performed simulation studies of Lasso variable selection precision (VSP) with and without nesting cross-validation within bootstrapping. Data were simulated to represent genomic data under a polygenic model as well as under a model with effect sizes representative of typical GWAS results. We compared these approaches to each other as well as to software defaults for the Lasso. Nested cross-validation had the most precise variable selection at small effect sizes. At larger effect sizes, there was no advantage to nesting. We illustrated the nested approach with empirical data comprising SNPs and SNP-SNP interactions from the most significant SNPs in a GWAS of borderline personality symptoms. In the empirical example, we found that the default Lasso selected low-reliability SNPs and interactions which were excluded by bootstrapping. PMID:27248122

  4. The application of the statistical bootstrap model to particle production in hadron-hadron collisions

    International Nuclear Information System (INIS)

    The following applications of the statistical bootstrap model (SBM) to hadron production in hadron-hadron collisions are discussed: (1) the independent fireball production model (IFPM); (2) single particle distributions in the IFPM (thermodynamic model); (3) production of heavy particles and pairs of heavy particles; (4) two-particle distributions and correlations in the IFPM and the Bose effect; (5) large psub(perpendicular) phenomena and fireball models; (6) N anti N annihilation at rest in the SBM. (author)

  5. Extending Bootstrap

    CERN Document Server

    Niska, Christoffer

    2014-01-01

    Practical and instruction-based, this concise book will take you from understanding what Bootstrap is, to creating your own Bootstrap theme in no time! If you are an intermediate front-end developer or designer who wants to learn the secrets of Bootstrap, this book is perfect for you.

  6. Bootstrap Results From the State Space From Representation of the Heath-Jarrow-Morton Model

    OpenAIRE

    Ram Bhar; Carl Chiarella

    1996-01-01

    This paper builds upon the authors' previous work on transformation of the Heath-Jarrow-Morton (HJM) model of the term structure of interest rates to state space form for a fairly general class of volatility specification including stochastic variables. Estimation of this volatility function is at the heart of the identification of the HJM model. The paper develops a bootstrap procedure for the HJM model cast into the non-linear filtering framework to analyse the statistical significance of t...

  7. Surrogate model of acetylene hydrogenation reactor based on bootstrap GEI algorithm%基于bootstrap GEI算法的碳二加氢反应器代理模型

    Institute of Scientific and Technical Information of China (English)

    段星辰; 杜文莉

    2015-01-01

    Acetylene hydrogenation reactor is an important device of the ethylene plant, and its working condition directly affects the purity and yield of ethylene products, so it is of great significance to improve the modeling and optimization efficiency of the reaction process for acetylene hydrogenation. However, directly optimizing high precision CFD models are often low efficiency because of the large calculation. This paper from the model accuracy of prediction variance and improvement of the effectiveness of global search, proposes a bootstrap GEI algorithm based on Kriging surrogate model. Through simulation contrast of test functions, compared with bootstrap EI algorithm, this algorithm can find the optimal sample points of global search and reduce the number of sample points, so as to improve the efficiency of the model updating and optimization. And this algorithm is effectively validated in the surrogate model of acetylene hydrogenation reactor.%碳二加氢反应器是乙烯工厂的一个重要装置,其运行状况直接影响着乙烯产品的纯度和产量,因此,提高碳二加氢反应过程的建模和优化效率对于工业实际具有重要意义.但是,直接对碳二加氢反应器的CFD高精度分析模型进行优化,计算量大,优化效率非常低.本文从模型预测方差准确性和提高全局搜索的有效性出发,基于Kriging代理模型,提出了一种求取无偏预测方差的广义期望提高算法——bootstrap GEI算法,通过测试函数的仿真对比,与bootstrap EI算法相比,该算法能够从全局角度搜索最优样本点,减少样本点的个数,从而提高模型更新和优化效率.该算法在实际工业碳二加氢等温反应器的代理模型中也得到了有效验证.

  8. Violation of KNO scaling and the NBD phenomenon in the framework of the statistical bootstrap model

    Science.gov (United States)

    Kokoulina, E. S.; Kuvshinov, V. I.

    1991-05-01

    The connection is considered of multiplicity distributions in three stages: partonic, hadronization, and hadronic. An interpretation of the LoPHD parameter is found. It is shown that under specific hypotheses on the form of the mass spectrum, the statistical bootstrap model leads to the negative binomial distribution (NBD) at the hadronic stage of development of the multiple production process with specific analytic dependences of the parameters of the NBD.

  9. Bootstrap data methodology for sequential hybrid model building

    Science.gov (United States)

    Volponi, Allan J. (Inventor); Brotherton, Thomas (Inventor)

    2007-01-01

    A method for modeling engine operation comprising the steps of: 1. collecting a first plurality of sensory data, 2. partitioning a flight envelope into a plurality of sub-regions, 3. assigning the first plurality of sensory data into the plurality of sub-regions, 4. generating an empirical model of at least one of the plurality of sub-regions, 5. generating a statistical summary model for at least one of the plurality of sub-regions, 6. collecting an additional plurality of sensory data, 7. partitioning the second plurality of sensory data into the plurality of sub-regions, 8. generating a plurality of pseudo-data using the empirical model, and 9. concatenating the plurality of pseudo-data and the additional plurality of sensory data to generate an updated empirical model and an updated statistical summary model for at least one of the plurality of sub-regions.

  10. Pragmatic Bootstrapping: A Neural Network Model of Vocabulary Acquisition

    Science.gov (United States)

    Caza, Gregory A.; Knott, Alistair

    2012-01-01

    The social-pragmatic theory of language acquisition proposes that children only become efficient at learning the meanings of words once they acquire the ability to understand the intentions of other agents, in particular the intention to communicate (Akhtar & Tomasello, 2000). In this paper we present a neural network model of word learning which…

  11. Analyzing short time series data from periodically fluctuating rodent populations by threshold models: A nearest block bootstrap approach

    Institute of Scientific and Technical Information of China (English)

    CHAN Kung-Sik; TONG Howell; STENSETH Nils Chr

    2009-01-01

    The study of the rodent fluctuations of the North was initiated in its modern form with Elton's pioneering work. Many scientific studies have been designed to collect yearly rodent abundance data, but the resulting time series are generally subject to at least two "problems": being short and non-linear. We explore the use of the continuous threshold autoregressive (TAR) models for analyzing such data. In the simplest case, the continuous TAR models are additive autoregressive models, being piecewise linear in one lag, and linear in all other lags. The location of the slope change is called the threshold parameter. The continuous TAR models for rodent abundance data can be derived from a general prey-predator model under some simplifying assumptions. The lag in which the threshold is located sheds important insights on the structure of the prey-predator system. We propose to assess the uncertainty on the location of the threshold via a new bootstrap called the nearest block bootstrap (NBB) which combines the methods of moving block bootstrap and the nearest neighbor bootstrap.The NBB assumes an underlying finite-order time-homogeneous Markov process. Essentially, the NBB bootstraps blocks of random block sizes, with each block being drawn from a non-parametric estimate of the future distribution given the realized past bootstrap series. We illustrate the methods by simulations and on a particular rodent abundance time series from Kilpisjarvi, Northern Finland.

  12. PENGGUNAAN BOOTSTRAP DATA DEPENDEN UNTUK MEMBANGUN SELANG KEPERCAYAAN PADA PARAMETER MODEL PERAMALAN DATA STASIONER

    OpenAIRE

    Siana Halim; Herman Mallian

    2006-01-01

    The Bootstrap is a lively research area. A lot Of ideas are around and have let to quiet different proposals. In this paper we sketch briefly some Bootstrap methods for independent and dependent data. Finally we give an Bootstrap example for constructing confidence interval in the forecasting for stationer data. Abstract in Bahasa Indonesia : Bootstrap merupakan area penelitian yang terus berkembang. Ada banyak ide dan proposal-proposal yang berbeda telah diberikan oleh para peneliti. Namun d...

  13. The Effective Bootstrap

    CERN Document Server

    Echeverri, Alejandro Castedo; Serone, Marco

    2016-01-01

    We study the numerical bounds obtained using a conformal-bootstrap method - advocated in ref. [1] but never implemented so far - where different points in the plane of conformal cross ratios $z$ and $\\bar z$ are sampled. In contrast to the most used method based on derivatives evaluated at the symmetric point $z=\\bar z =1/2$, we can consistently "integrate out" higher-dimensional operators and get a reduced simpler, and faster to solve, set of bootstrap equations. We test this "effective" bootstrap by studying the 3D Ising and $O(n)$ vector models and bounds on generic 4D CFTs, for which extensive results are already available in the literature. We also determine the scaling dimensions of certain scalar operators in the $O(n)$ vector models, with $n=2,3,4$, which have not yet been computed using bootstrap techniques.

  14. The effective bootstrap

    Science.gov (United States)

    Echeverri, Alejandro Castedo; von Harling, Benedict; Serone, Marco

    2016-09-01

    We study the numerical bounds obtained using a conformal-bootstrap method — advocated in ref. [1] but never implemented so far — where different points in the plane of conformal cross ratios z and overline{z} are sampled. In contrast to the most used method based on derivatives evaluated at the symmetric point z=overline{z}=1/2 , we can consistently "integrate out" higher-dimensional operators and get a reduced simpler, and faster to solve, set of bootstrap equations. We test this "effective" bootstrap by studying the 3D Ising and O( n) vector models and bounds on generic 4D CFTs, for which extensive results are already available in the literature. We also determine the scaling dimensions of certain scalar operators in the O( n) vector models, with n = 2, 3, 4, which have not yet been computed using bootstrap techniques.

  15. A bootstrapping soft shrinkage approach for variable selection in chemical modeling.

    Science.gov (United States)

    Deng, Bai-Chuan; Yun, Yong-Huan; Cao, Dong-Sheng; Yin, Yu-Long; Wang, Wei-Ting; Lu, Hong-Mei; Luo, Qian-Yi; Liang, Yi-Zeng

    2016-02-18

    In this study, a new variable selection method called bootstrapping soft shrinkage (BOSS) method is developed. It is derived from the idea of weighted bootstrap sampling (WBS) and model population analysis (MPA). The weights of variables are determined based on the absolute values of regression coefficients. WBS is applied according to the weights to generate sub-models and MPA is used to analyze the sub-models to update weights for variables. The optimization procedure follows the rule of soft shrinkage, in which less important variables are not eliminated directly but are assigned smaller weights. The algorithm runs iteratively and terminates until the number of variables reaches one. The optimal variable set with the lowest root mean squared error of cross-validation (RMSECV) is selected. The method was tested on three groups of near infrared (NIR) spectroscopic datasets, i.e. corn datasets, diesel fuels datasets and soy datasets. Three high performing variable selection methods, i.e. Monte Carlo uninformative variable elimination (MCUVE), competitive adaptive reweighted sampling (CARS) and genetic algorithm partial least squares (GA-PLS) are used for comparison. The results show that BOSS is promising with improved prediction performance. The Matlab codes for implementing BOSS are freely available on the website: http://www.mathworks.com/matlabcentral/fileexchange/52770-boss. PMID:26826688

  16. Survey bootstrap and bootstrap weights

    OpenAIRE

    Stas Kolenikov

    2008-01-01

    In this presentation, I will review the bootstrap for complex surveys with designs featuring stratification, clustering, and unequal probability weights. I will present the Stata module bsweights, which creates the bootstrap weights for designs specified through and supported by svy. I will also provide simple demonstrations highlighting the use of the procedure and its syntax. I will discuss various tuning parameters and their impact on the performance of the procedure, and I will give argum...

  17. Comparison of bootstrap current and plasma conductivity models applied in a self-consistent equilibrium calculation for Tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Maria Celia Ramos; Ludwig, Gerson Otto [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Lab. Associado de Plasma]. E-mail: mcr@plasma.inpe.br

    2004-07-01

    Different bootstrap current formulations are implemented in a self-consistent equilibrium calculation obtained from a direct variational technique in fixed boundary tokamak plasmas. The total plasma current profile is supposed to have contributions of the diamagnetic, Pfirsch-Schlueter, and the neoclassical Ohmic and bootstrap currents. The Ohmic component is calculated in terms of the neoclassical conductivity, compared here among different expressions, and the loop voltage determined consistently in order to give the prescribed value of the total plasma current. A comparison among several bootstrap current models for different viscosity coefficient calculations and distinct forms for the Coulomb collision operator is performed for a variety of plasma parameters of the small aspect ratio tokamak ETE (Experimento Tokamak Esferico) at the Associated Plasma Laboratory of INPE, in Brazil. We have performed this comparison for the ETE tokamak so that the differences among all the models reported here, mainly regarding plasma collisionality, can be better illustrated. The dependence of the bootstrap current ratio upon some plasma parameters in the frame of the self-consistent calculation is also analysed. We emphasize in this paper what we call the Hirshman-Sigmar/Shaing model, valid for all collisionality regimes and aspect ratios, and a fitted formulation proposed by Sauter, which has the same range of validity but is faster to compute than the previous one. The advantages or possible limitations of all these different formulations for the bootstrap current estimate are analysed throughout this work. (author)

  18. The bootstrapped model--Lessons for the acceptance of intellectual technology.

    Science.gov (United States)

    Lovie, A D

    1987-09-01

    This paper is intended as a non-technical introduction to a growing aspect of what has been termed 'intellectual technology'. The particular area chosen is the use of simple linear additive models for judgement and decision making purposes. Such models are said to either outperform, or perform at least as well as, the human judges on which they are based, hence they are said to 'bootstrap' such human inputs. Although the paper will provide a fairly comprehensive list of recent applications of such models, from postgraduate selection to judgements of marital happiness, the work will concentrate on the topic of Credit Scoring as an exemplar - that is, the assignment of credit by means of a simple additive rule. The paper will also present a simple system, due to Dawes, of classifying such models according to the form and source of their weights. The paper further discusses the reasons for bootstrapping and that other major phenomenon of such models - that is, the one can rarely distinguish between the prescriptions of such models, however the weights have been arrived at. It is argued that this 'principle of the flat maximum' allows us to develop a technology of judgement. The paper continues with a brief historical survey of the reactions of human experts to such models and their superiority, and suggestions for a better mix of expert and model on human engineering lines. Finally, after a brief comparison between expert systems and linear additive models, the paper concludes with a brief survey of possible future developments. A short Appendix describes two applications of such models.

  19. Applying the Bollen-Stine Bootstrap for Goodness-of-Fit Measures to Structural Equation Models with Missing Data.

    Science.gov (United States)

    Enders, Craig K.

    2002-01-01

    Proposed a method for extending the Bollen-Stine bootstrap model (K. Bollen and R. Stine, 1992) fit to structural equation models with missing data. Developed a Statistical Analysis System macro program to implement this procedure, and assessed its usefulness in a simulation. The new method yielded model rejection rates close to the nominal 5%…

  20. On the Model-Based Bootstrap with Missing Data: Obtaining a "P"-Value for a Test of Exact Fit

    Science.gov (United States)

    Savalei, Victoria; Yuan, Ke-Hai

    2009-01-01

    Evaluating the fit of a structural equation model via bootstrap requires a transformation of the data so that the null hypothesis holds exactly in the sample. For complete data, such a transformation was proposed by Beran and Srivastava (1985) for general covariance structure models and applied to structural equation modeling by Bollen and Stine…

  1. Poor (wo)man's bootstrap

    OpenAIRE

    Bo E. Honoré; Hu, Luojia

    2015-01-01

    The bootstrap is a convenient tool for calculating standard errors of the parameters of complicated econometric models. Unfortunately, the fact that these models are complicated often makes the bootstrap extremely slow or even practically infeasible. This paper proposes an alternative to the bootstrap that relies only on the estimation of one-dimensional parameters. The paper contains no new difficult math. But we believe that it can be useful.

  2. Analyzing short time series data from periodically fluctuating rodent populations by threshold models:A nearest block bootstrap approach

    Institute of Scientific and Technical Information of China (English)

    CHAN; Kung-Sik; TONG; Howell; STENSETH; Nils; Chr

    2009-01-01

    The study of the rodent fluctuations of the North was initiated in its modern form with Elton’s pioneering work.Many scientific studies have been designed to collect yearly rodent abundance data,but the resulting time series are generally subject to at least two "problems":being short and non-linear.We explore the use of the continuous threshold autoregressive(TAR) models for analyzing such data.In the simplest case,the continuous TAR models are additive autoregressive models,being piecewise linear in one lag,and linear in all other lags.The location of the slope change is called the threshold parameter.The continuous TAR models for rodent abundance data can be derived from a general prey-predator model under some simplifying assumptions.The lag in which the threshold is located sheds important insights on the structure of the prey-predator system.We propose to assess the uncertainty on the location of the threshold via a new bootstrap called the nearest block bootstrap(NBB) which combines the methods of moving block bootstrap and the nearest neighbor bootstrap.The NBB assumes an underlying finite-order time-homogeneous Markov process.Essentially,the NBB bootstraps blocks of random block sizes,with each block being drawn from a non-parametric estimate of the future distribution given the realized past bootstrap series.We illustrate the methods by simulations and on a particular rodent abundance time series from Kilpisjrvi,Northern Finland.

  3. Bootstrapping in a language of thought: a formal model of numerical concept learning.

    Science.gov (United States)

    Piantadosi, Steven T; Tenenbaum, Joshua B; Goodman, Noah D

    2012-05-01

    In acquiring number words, children exhibit a qualitative leap in which they transition from understanding a few number words, to possessing a rich system of interrelated numerical concepts. We present a computational framework for understanding this inductive leap as the consequence of statistical inference over a sufficiently powerful representational system. We provide an implemented model that is powerful enough to learn number word meanings and other related conceptual systems from naturalistic data. The model shows that bootstrapping can be made computationally and philosophically well-founded as a theory of number learning. Our approach demonstrates how learners may combine core cognitive operations to build sophisticated representations during the course of development, and how this process explains observed developmental patterns in number word learning.

  4. Wild Bootstrap Versus Moment-Oriented Bootstrap

    OpenAIRE

    Sommerfeld, Volker

    1997-01-01

    We investigate the relative merits of a “moment-oriented” bootstrap method of Bunke (1997) in comparison with the classical wild bootstrap of Wu (1986) in nonparametric heteroscedastic regression situations. The “moment-oriented” bootstrap is a wild bootstrap based on local estimators of higher order error moments that are smoothed by kernel smoothers. In this paper we perform an asymptotic comparison of these two dierent bootstrap procedures. We show that the moment-oriented bootstrap is in ...

  5. Bootstrap essentials

    CERN Document Server

    Bhaumik, Snig

    2015-01-01

    If you are a web developer who designs and develops websites and pages using HTML, CSS, and JavaScript, but have very little familiarity with Bootstrap, this is the book for you. Previous experience with HTML, CSS, and JavaScript will be helpful, while knowledge of jQuery would be an extra advantage.

  6. Bootstrap unloader

    Science.gov (United States)

    Pfiffner, H. J.

    1969-01-01

    Circuit can sample a number of transducers in sequence without drawing from them. This bootstrap unloader uses a differential amplifier with one input connected to a circuit which is the equivalent of the circuit to be unloaded, and the other input delivering the proper unloading currents.

  7. Bootstrap Sequential Determination of the Co-integration Rank in VAR Models

    DEFF Research Database (Denmark)

    Guiseppe, Cavaliere; Rahbæk, Anders; Taylor, A.M. Robert

    empirical rejection frequencies often very much in excess of the nominal level. As a consequence, bootstrap versions of these tests have been developed. To be useful, however, sequential procedures for determining the co-integrating rank based on these bootstrap tests need to be consistent, in the sense...... we fill this gap in the literature by proposing a bootstrap sequential algorithm which we demonstrate delivers consistent cointegration rank estimation for general I(1) processes. Finite sample Monte Carlo simulations show the proposed procedure performs well in practice....

  8. Sensitivity Analysis to Efficiency Scores : How to Bootstrap in Nonparametric Frontier Models

    OpenAIRE

    Simar, Léopold; Wilson, Paul

    1995-01-01

    Efficiency scores of production units are generally measured relative to an estimated production frontier. Nonparametric estimators (DEA, FDH, ... ) are based on a finite sample of observed production units. The bootstrap is one easy way to analyze the sensitivity of efficiency scores relative to the sampling variations of the estimated frontier. The main point in order to validate the bootstrap is to define a reasonable data generating process in this complex framework and to propose a reaso...

  9. Sensitivity Analysis of Efficiency Scores: How to Bootstrap in Nonparametric Frontier Models

    OpenAIRE

    Simar, Léopold; Paul W. Wilson

    1998-01-01

    Efficiency scores of production units are generally measured relative to an estimated production frontier. Nonparametric estimators (DEA, FDH, \\cdots ) are based on a finite sample of observed production units. The bootstrap is one easy way to analyze the sensitivity of efficiency scores relative to the sampling variations of the estimated frontier. The main point in order to validate the bootstrap is to define a reasonable data-generating process in this complex framework and to propose a re...

  10. Point Set Denoising Using Bootstrap-Based Radial Basis Function

    Science.gov (United States)

    Ramli, Ahmad; Abd. Majid, Ahmad

    2016-01-01

    This paper examines the application of a bootstrap test error estimation of radial basis functions, specifically thin-plate spline fitting, in surface smoothing. The presence of noisy data is a common issue of the point set model that is generated from 3D scanning devices, and hence, point set denoising is one of the main concerns in point set modelling. Bootstrap test error estimation, which is applied when searching for the smoothing parameters of radial basis functions, is revisited. The main contribution of this paper is a smoothing algorithm that relies on a bootstrap-based radial basis function. The proposed method incorporates a k-nearest neighbour search and then projects the point set to the approximated thin-plate spline surface. Therefore, the denoising process is achieved, and the features are well preserved. A comparison of the proposed method with other smoothing methods is also carried out in this study. PMID:27315105

  11. Seven Stages of Bootstrap

    OpenAIRE

    Beran, Rudolf

    1994-01-01

    This essay is organized around the theoretical and computationalproblem of constructing bootstrap confidence sets, with forays into relatedtopics. The seven section headings are: Introduction; The Bootstrap World;Bootstrap Confidence Sets; Computing Bootstrap Confidence Sets; Quality ofBootstrap Confidence Sets; Iterated and Two-step Boostrap; Further Resources.

  12. A bootstrap method for estimating bias and variance in statistical fisheries modelling frameworks using highly disparate datasets

    OpenAIRE

    Elvarsson, B. P.; Taylor, L.; Trenkel, Verena; Kupca, V.; Stefansson, G.

    2014-01-01

    Statistical models of marine ecosystems use a variety of data sources to estimate parameters using composite or weighted likelihood functions with associated weighting issues and questions on how to obtain variance estimates. Regardless of the method used to obtain point estimates, a method is required for variance estimation. A bootstrap technique is introduced for the evaluation of uncertainty in such models, taking into account inherent spatial and temporal correlations in the datasets, wh...

  13. Bootstrap Sequential Determination of the Co-integration Rank in VAR Models

    DEFF Research Database (Denmark)

    Cavaliere, Giuseppe; Rahbek, Anders; Taylor, A. M. Robert

    empirical rejection frequencies often very much in excess of the nominal level. As a consequence, bootstrap versions of these tests have been developed. To be useful, however, sequential procedures for determining the co-integrating rank based on these bootstrap tests need to be consistent, in the sense...... that the probability of selecting a rank smaller than (equal to) the true co-integrating rank will converge to zero (one minus the marginal significance level), as the sample size diverges, for general I(1) processes. No such likelihood-based procedure is currently known to be available. In this paper...... we fill this gap in the literature by proposing a bootstrap sequential algorithm which we demonstrate delivers consistent cointegration rank estimation for general I(1) processes. Finite sample Monte Carlo simulations show the proposed procedure performs well in practice....

  14. Chaos Expansion Based Bootstrap Filter To Calibrate CO2 Injection Models

    Science.gov (United States)

    Oladyshkin, Sergey; Schröder, Patrick; Class, Holger; Nowak, Wolfgang

    2013-04-01

    dependence of the model on these multipliers with the response surface. Step two consists of Bayesian updating in order to match the reduced model to past or real-time observations of system behavior (e.g. past production data or pressure at monitoring wells during a certain time period). In this step we apply Bootstrap filtering on the response surface constructed in step one. Bootstrap filtering is a fully non-linear and Bayesian approach to the inverse problem in history matching, more accurate than Ensemble Kalman filters. As a specific methodological focus, ensuring that the expansion remains optimal even if the updated parameter values are far from their prior expansion, we will iterate between Step 1 and Step 2, so that the PCE expansion will be repeated successively. This may be interpreted as a high-order expansion equivalent to successive linearization.

  15. Mobile-first Bootstrap

    CERN Document Server

    Magno, Alexandre

    2013-01-01

    A practical, step-by-step tutorial on developing websites for mobile using Bootstrap.This book is for anyone who wants to get acquainted with the new features available in Bootstrap 3 and who wants to develop websites with the mobile-first feature of Bootstrap. The reader should have a basic knowledge of Bootstrap as a frontend framework.

  16. A Score Based Approach to Wild Bootstrap Inference

    OpenAIRE

    Patrick M. Kline; Andres Santos

    2010-01-01

    We propose a generalization of the wild bootstrap of Wu (1986) and Liu (1988) based upon perturbing the scores of M-estimators. This "score bootstrap" procedure avoids recomputing the estimator in each bootstrap iteration, making it substantially less costly to compute than the conventional nonparametric bootstrap, particularly in complex nonlinear models. Despite this computational advantage, in the linear model, the score bootstrap studentized test statistic is equivalent to that of the con...

  17. The conformal bootstrap

    Science.gov (United States)

    Poland, David; Simmons-Duffin, David

    2016-06-01

    The conformal bootstrap was proposed in the 1970s as a strategy for calculating the properties of second-order phase transitions. After spectacular success elucidating two-dimensional systems, little progress was made on systems in higher dimensions until a recent renaissance beginning in 2008. We report on some of the main results and ideas from this renaissance, focusing on new determinations of critical exponents and correlation functions in the three-dimensional Ising and O(N) models.

  18. Applications of threshold models and the weighted bootstrap for Hungarian precipitation data

    Science.gov (United States)

    Varga, László; Rakonczai, Pál; Zempléni, András

    2016-05-01

    This paper presents applications of the peaks-over-threshold methodology for both the univariate and the recently introduced bivariate case, combined with a novel bootstrap approach. We compare the proposed bootstrap methods to the more traditional profile likelihood. We have investigated 63 years of the European Climate Assessment daily precipitation data for five Hungarian grid points, first separately for the summer and winter months, then aiming at the detection of possible changes by investigating 20 years moving windows. We show that significant changes can be observed both in the univariate and the bivariate cases, the most recent period being the most dangerous in several cases, as some return values have increased substantially. We illustrate these effects by bivariate coverage regions.

  19. Bootstrapping integrated covariance matrix estimators in noisy jump-diffusion models with non-synchronous trading

    DEFF Research Database (Denmark)

    Hounyo, Ulrich

    We propose a bootstrap mehtod for estimating the distribution (and functionals of it such as the variance) of various integrated covariance matrix estimators. In particular, we first adapt the wild blocks of blocks bootsratp method suggested for the pre-averaged realized volatility estimator to a...... the finite sample properties of the existing first-order asymptotic theory. We illustrate its practical use on high-frequency equity data...

  20. Bootstrapping phylogenies inferred from rearrangement data

    Directory of Open Access Journals (Sweden)

    Lin Yu

    2012-08-01

    Full Text Available Abstract Background Large-scale sequencing of genomes has enabled the inference of phylogenies based on the evolution of genomic architecture, under such events as rearrangements, duplications, and losses. Many evolutionary models and associated algorithms have been designed over the last few years and have found use in comparative genomics and phylogenetic inference. However, the assessment of phylogenies built from such data has not been properly addressed to date. The standard method used in sequence-based phylogenetic inference is the bootstrap, but it relies on a large number of homologous characters that can be resampled; yet in the case of rearrangements, the entire genome is a single character. Alternatives such as the jackknife suffer from the same problem, while likelihood tests cannot be applied in the absence of well established probabilistic models. Results We present a new approach to the assessment of distance-based phylogenetic inference from whole-genome data; our approach combines features of the jackknife and the bootstrap and remains nonparametric. For each feature of our method, we give an equivalent feature in the sequence-based framework; we also present the results of extensive experimental testing, in both sequence-based and genome-based frameworks. Through the feature-by-feature comparison and the experimental results, we show that our bootstrapping approach is on par with the classic phylogenetic bootstrap used in sequence-based reconstruction, and we establish the clear superiority of the classic bootstrap for sequence data and of our corresponding new approach for rearrangement data over proposed variants. Finally, we test our approach on a small dataset of mammalian genomes, verifying that the support values match current thinking about the respective branches. Conclusions Our method is the first to provide a standard of assessment to match that of the classic phylogenetic bootstrap for aligned sequences. Its

  1. Bootstrap rank-ordered conditional mutual information (broCMI): A nonlinear input variable selection method for water resources modeling

    Science.gov (United States)

    Quilty, John; Adamowski, Jan; Khalil, Bahaa; Rathinasamy, Maheswaran

    2016-03-01

    The input variable selection problem has recently garnered much interest in the time series modeling community, especially within water resources applications, demonstrating that information theoretic (nonlinear)-based input variable selection algorithms such as partial mutual information (PMI) selection (PMIS) provide an improved representation of the modeled process when compared to linear alternatives such as partial correlation input selection (PCIS). PMIS is a popular algorithm for water resources modeling problems considering nonlinear input variable selection; however, this method requires the specification of two nonlinear regression models, each with parametric settings that greatly influence the selected input variables. Other attempts to develop input variable selection methods using conditional mutual information (CMI) (an analog to PMI) have been formulated under different parametric pretenses such as k nearest-neighbor (KNN) statistics or kernel density estimates (KDE). In this paper, we introduce a new input variable selection method based on CMI that uses a nonparametric multivariate continuous probability estimator based on Edgeworth approximations (EA). We improve the EA method by considering the uncertainty in the input variable selection procedure by introducing a bootstrap resampling procedure that uses rank statistics to order the selected input sets; we name our proposed method bootstrap rank-ordered CMI (broCMI). We demonstrate the superior performance of broCMI when compared to CMI-based alternatives (EA, KDE, and KNN), PMIS, and PCIS input variable selection algorithms on a set of seven synthetic test problems and a real-world urban water demand (UWD) forecasting experiment in Ottawa, Canada.

  2. Bootstrapping O( N ) vector models with four supercharges in 3 ≤ d ≤ 4

    Science.gov (United States)

    Chester, Shai M.; Iliesiu, Luca V.; Pufu, Silviu S.; Yacoby, Ran

    2016-05-01

    We analyze the conformal bootstrap constraints in theories with four super-charges and a global O( N ) × U(1) flavor symmetry in 3 ≤ d ≤ 4 dimensions. In particular, we consider the 4-point function of O( N )-fundamental chiral operators Z i that have no chiral primary in the O( N )-singlet sector of their OPE. We find features in our numerical bounds that nearly coincide with the theory of N + 1 chiral super-fields with superpotential W = X∑ i = 1 N Z i 2 as well as general bounds on SCFTs where ∑ i = 1 N Z i 2 vanishes in the chiral ring.

  3. Bootstrapping Mixed Correlators in the Five Dimensional Critical O(N) Models

    CERN Document Server

    Li, Zhijin

    2016-01-01

    We use the conformal bootstrap approach to explore $5D$ CFTs with $O(N)$ global symmetry, which contain $N$ scalars $\\phi_i$ transforming as $O(N)$ vector. Specifically, we study multiple four-point correlators of the leading $O(N)$ vector $\\phi_i$ and the $O(N)$ singlet $\\sigma$. The crossing symmetry of the four-point functions and the unitarity condition provide nontrivial constraints on the scaling dimensions ($\\Delta_\\phi$, $\\Delta_\\sigma$) of $\\phi_i$ and $\\sigma$. With reasonable assumptions on the gaps between scaling dimensions of $\\phi_i$ ($\\sigma$) and the next $O(N)$ vector (singlet) scalar, we are able to isolate the scaling dimensions $(\\Delta_\\phi$, $\\Delta_\\sigma)$ in small islands. In particular, for large $N=500$, the isolated region is highly consistent with the result obtained from large $N$ expansion. We also study the interacting $O(N)$ CFTs for $1\\leqslant N\\leqslant100$. Isolated regions on $(\\Delta_\\phi,\\Delta_\\sigma)$ plane are obtained using conformal bootstrap program with lower or...

  4. Evaluating experimental design for soil-plant model selection using a Bootstrap Filter and Bayesian model averaging

    Science.gov (United States)

    Wöhling, T.; Schöniger, A.; Geiges, A.; Nowak, W.; Gayler, S.

    2013-12-01

    The objective selection of appropriate models for realistic simulations of coupled soil-plant processes is a challenging task since the processes are complex, not fully understood at larger scales, and highly non-linear. Also, comprehensive data sets are scarce, and measurements are uncertain. In the past decades, a variety of different models have been developed that exhibit a wide range of complexity regarding their approximation of processes in the coupled model compartments. We present a method for evaluating experimental design for maximum confidence in the model selection task. The method considers uncertainty in parameters, measurements and model structures. Advancing the ideas behind Bayesian Model Averaging (BMA), we analyze the changes in posterior model weights and posterior model choice uncertainty when more data are made available. This allows assessing the power of different data types, data densities and data locations in identifying the best model structure from among a suite of plausible models. The models considered in this study are the crop models CERES, SUCROS, GECROS and SPASS, which are coupled to identical routines for simulating soil processes within the modelling framework Expert-N. The four models considerably differ in the degree of detail at which crop growth and root water uptake are represented. Monte-Carlo simulations were conducted for each of these models considering their uncertainty in soil hydraulic properties and selected crop model parameters. Using a Bootstrap Filter (BF), the models were then conditioned on field measurements of soil moisture, matric potential, leaf-area index, and evapotranspiration rates (from eddy-covariance measurements) during a vegetation period of winter wheat at a field site at the Swabian Alb in Southwestern Germany. Following our new method, we derived model weights when using all data or different subsets thereof. We discuss to which degree the posterior mean outperforms the prior mean and all

  5. Bootstrapping 3D fermions

    Science.gov (United States)

    Iliesiu, Luca; Kos, Filip; Poland, David; Pufu, Silviu S.; Simmons-Duffin, David; Yacoby, Ran

    2016-03-01

    We study the conformal bootstrap for a 4-point function of fermions in 3D. We first introduce an embedding formalism for 3D spinors and compute the conformal blocks appearing in fermion 4-point functions. Using these results, we find general bounds on the dimensions of operators appearing in the ψ × ψ OPE, and also on the central charge C T . We observe features in our bounds that coincide with scaling dimensions in the GrossNeveu models at large N . We also speculate that other features could coincide with a fermionic CFT containing no relevant scalar operators.

  6. Bootstrapping $O(N)$ Vector Models with Four Supercharges in $3 \\leq d \\leq4$

    CERN Document Server

    Chester, Shai M; Pufu, Silviu S; Yacoby, Ran

    2015-01-01

    We analyze the conformal bootstrap constraints in theories with four supercharges and a global $O(N) \\times U(1)$ flavor symmetry in $3 \\leq d \\leq 4$ dimensions. In particular, we consider the 4-point function of $O(N)$-fundamental chiral operators $Z_i$ that have no chiral primary in the $O(N)$-singlet sector of their OPE. We find features in our numerical bounds that nearly coincide with the theory of $N+1$ chiral super-fields with superpotential $W = X \\sum_{i=1}^N Z_i^2$, as well as general bounds on SCFTs where $\\sum_{i=1}^N Z_i^2$ vanishes in the chiral ring.

  7. Efficient bootstrap with weakly dependent processes

    NARCIS (Netherlands)

    Bravo, Francesco; Crudu, Federico

    2012-01-01

    The efficient bootstrap methodology is developed for overidentified moment conditions models with weakly dependent observation. The resulting bootstrap procedure is shown to be asymptotically valid and can be used to approximate the distributions of t-statistics, the J-statistic for overidentifying

  8. A Bootstrap Approach of Benchmarking Organizational Maturity Model of Software Product With Educational Maturity Model

    Directory of Open Access Journals (Sweden)

    R.Manjula

    2012-06-01

    Full Text Available This Software product line engineering is an inter-disciplinary concept. It spans the dimensions of business, architecture, process, and the organization. Similarly, Education System engineering is also an inter-disciplinary concept, which spans the dimensions of academic, infrastructure, facilities, administration etc. Some of the potential benefits of this approach include continuous improvements in System quality and adhering to global standards. The increasing competency in IT and Educational Sectors necessitates a process maturity evaluation methodology. Accordingly, this paper presents an organizational maturity model for Education system for evaluating the maturity of multi- dimension factors and attributes of an Education System. Assessment questionnaires and a rating methodology comprise the framework of this Educational maturity model. The objective and design of the questionnaires are to collect information about the Education system engineering process from the multi perspectives of academic, infrastructure, administration, facilities etc. Furthermore, we conducted one case study and reported the assessment results using the organizational maturity model presented in this paper.

  9. Bootstrapping structured page segmentation

    Science.gov (United States)

    Ma, Huanfeng; Doermann, David S.

    2003-01-01

    In this paper, we present an approach to the bootstrap learning of a page segmentation model. The idea evolves from attempts to segment dictionaries that often have a consistent page structure, and is extended to the segmentation of more general structured documents. In cases of highly regular structure, the layout can be learned from examples of only a few pages. The system is first trained using a small number of samples, and a larger test set is processed based on the training result. After making corrections to a selected subset of the test set, these corrected samples are combined with the original training samples to generate bootstrap samples. The newly created samples are used to retrain the system, refine the learned features and resegment the test samples. This procedure is applied iteratively until the learned parameters are stable. Using this approach, we do not need to initially provide a large set of training samples. We have applied this segmentation to many structured documents such as dictionaries, phone books, spoken language transcripts, and obtained satisfying segmentation performance.

  10. Nonparametric bootstrap prediction

    OpenAIRE

    Fushiki, Tadayoshi; Komaki, Fumiyasu; Aihara, Kazuyuki

    2005-01-01

    Ensemble learning has recently been intensively studied in the field of machine learning. `Bagging' is a method of ensemble learning and uses bootstrap data to construct various predictors. The required prediction is then obtained by averaging the predictors. Harris proposed using this technique with the parametric bootstrap predictive distribution to construct predictive distributions, and showed that the parametric bootstrap predictive distribution gives asymptotically better prediction tha...

  11. Wild bootstrap of the mean in the infinite variance case

    OpenAIRE

    Giuseppe Cavaliere; Iliyan Georgiev; Robert Taylor, A. M.

    2011-01-01

    It is well known that the standard i.i.d. bootstrap of the mean is inconsistent in a location model with infinite variance (alfa-stable) innovations. This occurs because the bootstrap distribution of a normalised sum of infinite variance random variables tends to a random distribution. Consistent bootstrap algorithms based on subsampling methods have been proposed but have the drawback that they deliver much wider confidence sets than those generated by the i.i.d. bootstrap owing to the fact ...

  12. uniform bootstrap confidence bands for bounded influence curve estimators

    OpenAIRE

    Härdle, Wolfgang Karl; Ritov, Ya‘acov; Wang, Weining

    2013-01-01

    We consider theoretical bootstrap "coupling" techniques for nonparametric robust smoothers and quantile regression, and verify the bootstrap improvement. To cope with curse of dimensionality, a variant of "coupling" bootstrap techniques are developed for additive models with both symmetric error distributions and further extension to the quantile regression framework. Our bootstrap method can be used in many situations like constructing con dence intervals and bands. We demonstrate the bootst...

  13. Fast bootstrapping and permutation testing for assessing reproducibility and interpretability of multivariate fMRI decoding models.

    Directory of Open Access Journals (Sweden)

    Bryan R Conroy

    Full Text Available Multivariate decoding models are increasingly being applied to functional magnetic imaging (fMRI data to interpret the distributed neural activity in the human brain. These models are typically formulated to optimize an objective function that maximizes decoding accuracy. For decoding models trained on full-brain data, this can result in multiple models that yield the same classification accuracy, though some may be more reproducible than others--i.e. small changes to the training set may result in very different voxels being selected. This issue of reproducibility can be partially controlled by regularizing the decoding model. Regularization, along with the cross-validation used to estimate decoding accuracy, typically requires retraining many (often on the order of thousands of related decoding models. In this paper we describe an approach that uses a combination of bootstrapping and permutation testing to construct both a measure of cross-validated prediction accuracy and model reproducibility of the learned brain maps. This requires re-training our classification method on many re-sampled versions of the fMRI data. Given the size of fMRI datasets, this is normally a time-consuming process. Our approach leverages an algorithm called fast simultaneous training of generalized linear models (FaSTGLZ to create a family of classifiers in the space of accuracy vs. reproducibility. The convex hull of this family of classifiers can be used to identify a subset of Pareto optimal classifiers, with a single-optimal classifier selectable based on the relative cost of accuracy vs. reproducibility. We demonstrate our approach using full-brain analysis of elastic-net classifiers trained to discriminate stimulus type in an auditory and visual oddball event-related fMRI design. Our approach and results argue for a computational approach to fMRI decoding models in which the value of the interpretation of the decoding model ultimately depends upon optimizing a

  14. Bootstrap Dynamical Symmetry Breaking

    Directory of Open Access Journals (Sweden)

    Wei-Shu Hou

    2013-01-01

    Full Text Available Despite the emergence of a 125 GeV Higgs-like particle at the LHC, we explore the possibility of dynamical electroweak symmetry breaking by strong Yukawa coupling of very heavy new chiral quarks Q . Taking the 125 GeV object to be a dilaton with suppressed couplings, we note that the Goldstone bosons G exist as longitudinal modes V L of the weak bosons and would couple to Q with Yukawa coupling λ Q . With m Q ≳ 700  GeV from LHC, the strong λ Q ≳ 4 could lead to deeply bound Q Q ¯ states. We postulate that the leading “collapsed state,” the color-singlet (heavy isotriplet, pseudoscalar Q Q ¯ meson π 1 , is G itself, and a gap equation without Higgs is constructed. Dynamical symmetry breaking is affected via strong λ Q , generating m Q while self-consistently justifying treating G as massless in the loop, hence, “bootstrap,” Solving such a gap equation, we find that m Q should be several TeV, or λ Q ≳ 4 π , and would become much heavier if there is a light Higgs boson. For such heavy chiral quarks, we find analogy with the π − N system, by which we conjecture the possible annihilation phenomena of Q Q ¯ → n V L with high multiplicity, the search of which might be aided by Yukawa-bound Q Q ¯ resonances.

  15. Investigating Mortality Uncertainty Using the Block Bootstrap

    Directory of Open Access Journals (Sweden)

    Xiaoming Liu

    2010-01-01

    Full Text Available This paper proposes a block bootstrap method for measuring mortality risk under the Lee-Carter model framework. In order to take account of all sources of risk (the process risk, the parameter risk, and the model risk properly, a block bootstrap is needed to cope with the spatial dependence found in the residuals. As a result, the prediction intervals we obtain for life expectancy are more accurate than the ones obtained from other similar methods.

  16. Investigating Mortality Uncertainty Using the Block Bootstrap

    OpenAIRE

    Xiaoming Liu; W. John Braun

    2010-01-01

    This paper proposes a block bootstrap method for measuring mortality risk under the Lee-Carter model framework. In order to take account of all sources of risk (the process risk, the parameter risk, and the model risk) properly, a block bootstrap is needed to cope with the spatial dependence found in the residuals. As a result, the prediction intervals we obtain for life expectancy are more accurate than the ones obtained from other similar methods.

  17. Quarks in the Bootstrap Era

    Science.gov (United States)

    Horn, D.

    2015-03-01

    The quark model emerged from the Gell-Mann-Ne'eman flavor SU(3) symmetry. Its development, in the context of strong interactions, took place in a heuristic theoretical framework, referred to as the Bootstrap Era. Setting the background for the dominant ideas in strong interaction of the early 1960s, we outline some aspects of the constituent quark model. An independent theoretical development was the emergence of hadron duality in 1967, leading to a realization of the Bootstrap idea by relating hadron resonances (in the s-channel) with Regge pole trajectories (in t- and u-channels). The synthesis of duality with the quark-model has been achieved by duality diagrams, serving as a conceptual framework for discussing many aspects of hadron dynamics toward the end of the 1960s.

  18. Chain ladder method: Bayesian bootstrap versus classical bootstrap

    OpenAIRE

    Peters, Gareth W.; Mario V. W\\"uthrich; Shevchenko, Pavel V.

    2010-01-01

    The intention of this paper is to estimate a Bayesian distribution-free chain ladder (DFCL) model using approximate Bayesian computation (ABC) methodology. We demonstrate how to estimate quantities of interest in claims reserving and compare the estimates to those obtained from classical and credibility approaches. In this context, a novel numerical procedure utilising Markov chain Monte Carlo (MCMC), ABC and a Bayesian bootstrap procedure was developed in a truly distribution-free setting. T...

  19. Bootstrap percolation with inhibition

    OpenAIRE

    Einarsson, Hafsteinn; Lengler, Johannes; Panagiotou, Konstantinos; Mousset, Frank; Steger, Angelika

    2014-01-01

    Bootstrap percolation is a prominent framework for studying the spreading of activity on a graph. We begin with an initial set of active vertices. The process then proceeds in rounds, and further vertices become active as soon as they have a certain number of active neighbors. A recurring feature in bootstrap percolation theory is an `all-or-nothing' phenomenon: either the size of the starting set is so small that the process stops very soon, or it percolates (almost) completely. Motivated by...

  20. Dynamics of bootstrap percolation

    Indian Academy of Sciences (India)

    Prabodh Shukla

    2008-08-01

    Bootstrap percolation transition may be first order or second order, or it may have a mixed character where a first-order drop in the order parameter is preceded by critical fluctuations. Recent studies have indicated that the mixed transition is characterized by power-law avalanches, while the continuous transition is characterized by truncated avalanches in a related sequential bootstrap process. We explain this behaviour on the basis of an analytical and numerical study of the avalanche distributions on a Bethe lattice.

  1. Bootstrap Score Tests for Fractional Integration in Heteroskedastic ARFIMA Models, with an Application to Price Dynamics in Commodity Spot and Futures Markets

    DEFF Research Database (Denmark)

    Cavaliere, Giuseppe; Nielsen, Morten Ørregaard; Taylor, A.M. Robert

    Empirical evidence from time series methods which assume the usual I(0)/I(1) paradigm suggests that the efficient market hypothesis, stating that spot and futures prices of a commodity should cointegrate with a unit slope on futures prices, does not hold. However, these statistical methods...... fractionally integrated model we are able to find a body of evidence in support of the efficient market hypothesis for a number of commodities. Our new tests are wild bootstrap implementations of score-based tests for the order of integration of a fractionally integrated time series. These tests are designed...... principle do. A Monte Carlo simulation study demonstrates that very significant improvements infinite sample behaviour can be obtained by the bootstrap vis-à-vis the corresponding asymptotic tests in both heteroskedastic and homoskedastic environments....

  2. Wild cluster bootstrap confidence intervals

    OpenAIRE

    MacKinnon, James G.

    2014-01-01

    Confidence intervals based on cluster-robust covariance matrices can be constructed in many ways. In addition to conventional intervals obtained by inverting Wald (t) tests, the paper studies intervals obtained by inverting LM tests, studentized bootstrap intervals based on the wild cluster bootstrap, and restricted bootstrap intervals obtained by inverting bootstrap Wald and LM tests. It also studies the choice of an auxiliary distribution for the wild bootstrap, a modified covariance matrix...

  3. Breakdown theory for bootstrap quantiles

    OpenAIRE

    Singh, Kesar

    1998-01-01

    A general formula for computing the breakdown point in robustness for the $t$th bootstrap quantile of a statistic $T_n$ is obtained. The answer depends on $t$ and the breakdown point of $T_n$. Since the bootstrap quantiles are vital ingredients of bootstrap confidence intervals, the theory has implications pertaining to robustness of bootstrap confidence intervals. For certain $L$ and $M$ estimators, a robustification of bootstrap is suggested via the notion of Winsorization.

  4. Delta method and bootstrap in linear mixed models to estimate a proportion when no event is observed: application to intralesional resection in bone tumor surgery.

    Science.gov (United States)

    Francq, Bernard G; Cartiaux, Olivier

    2016-09-10

    Resecting bone tumors requires good cutting accuracy to reduce the occurrence of local recurrence. This issue is considerably reduced with a navigated technology. The estimation of extreme proportions is challenging especially with small or moderate sample sizes. When no success is observed, the commonly used binomial proportion confidence interval is not suitable while the rule of three provides a simple solution. Unfortunately, these approaches are unable to differentiate between different unobserved events. Different delta methods and bootstrap procedures are compared in univariate and linear mixed models with simulations and real data by assuming the normality. The delta method on the z-score and parametric bootstrap provide similar results but the delta method requires the estimation of the covariance matrix of the estimates. In mixed models, the observed Fisher information matrix with unbounded variance components should be preferred. The parametric bootstrap, easier to apply, outperforms the delta method for larger sample sizes but it may be time costly. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26990871

  5. Conformal Bootstrap in Mellin Space

    CERN Document Server

    Gopakumar, Rajesh; Sen, Kallol; Sinha, Aninda

    2016-01-01

    We propose a new approach towards analytically solving for the dynamical content of Conformal Field Theories (CFTs) using the bootstrap philosophy. This combines the original bootstrap idea of Polyakov with the modern technology of the Mellin representation of CFT amplitudes. We employ exchange Witten diagrams with built in crossing symmetry as our basic building blocks rather than the conventional conformal blocks in a particular channel. Demanding consistency with the operator product expansion (OPE) implies an infinite set of constraints on operator dimensions and OPE coefficients. We illustrate the power of this method in the epsilon expansion of the Wilson-Fisher fixed point by computing operator dimensions and, strikingly, OPE coefficients to higher orders in epsilon than currently available using other analytic techniques (including Feynman diagram calculations). Our results enable us to get a somewhat better agreement of certain observables in the 3d Ising model, with the precise numerical values that...

  6. Tie the straps: Uniform bootstrap con fidence bands for bounded influence curve estimators

    OpenAIRE

    Härdle, Wolfgang Karl; Ritov, Ya'Acov; Wang, Weining

    2013-01-01

    We consider theoretical bootstrap coupling techniques for nonparametric robust smoothers and quantile regression, and verify the bootstrap improvement. To cope with curse of dimensionality, a variant of coupling bootstrap techniques are developed for additive models with both symmetric error distributions and further extension to the quantile regression framework. Our bootstrap method can be used in many situations like constructing con dence intervals and bands. We demonstrate the bootstrap ...

  7. Closure of the Operator Product Expansion in the Non-Unitary Bootstrap

    CERN Document Server

    Esterlis, Ilya; Ramirez, David

    2016-01-01

    We use the numerical conformal bootstrap in two dimensions to search for finite, closed sub-algebras of the operator product expansion (OPE), without assuming unitarity. We find the minimal models as special cases, as well as additional lines of solutions that can be understood in the Coulomb gas formalism. All the solutions we find that contain the vacuum in the operator algebra are cases where the external operators of the bootstrap equation are degenerate operators, and we argue that this follows analytically from the expressions in arXiv:1202.4698 for the crossing matrices of Virasoro conformal blocks. Our numerical analysis is a special case of the "Gliozzi" bootstrap method, and provides a simpler setting in which to study technical challenges with the method. In the supplementary material, we provide a Mathematica notebook that automates the calculation of the crossing matrices and OPE coefficients for degenerate operators using the formulae of Dotsenko and Fateev.

  8. Bootstrapping Time Dilation Decoherence

    Science.gov (United States)

    Gooding, Cisco; Unruh, William G.

    2015-10-01

    We present a general relativistic model of a spherical shell of matter with a perfect fluid on its surface coupled to an internal oscillator, which generalizes a model recently introduced by the authors to construct a self-gravitating interferometer (Gooding and Unruh in Phys Rev D 90:044071, 2014). The internal oscillator evolution is defined with respect to the local proper time of the shell, allowing the oscillator to serve as a local clock that ticks differently depending on the shell's position and momentum. A Hamiltonian reduction is performed on the system, and an approximate quantum description is given to the reduced phase space. If we focus only on the external dynamics, we must trace out the clock degree of freedom, and this results in a form of intrinsic decoherence that shares some features with a proposed "universal" decoherence mechanism attributed to gravitational time dilation (Pikovski et al in Nat Phys, 2015). We note that the proposed decoherence remains present in the (gravity-free) limit of flat spacetime, emphasizing that the effect can be attributed entirely to proper time differences, and thus is not necessarily related to gravity. Whereas the effect described in (Pikovski et al in Nat Phys, 2015) vanishes in the absence of an external gravitational field, our approach bootstraps the gravitational contribution to the time dilation decoherence by including self-interaction, yielding a fundamentally gravitational intrinsic decoherence effect.

  9. Bootstrapping topology and systemic risk of complex network using the fitness model

    OpenAIRE

    Musmeci N.; Battiston S.; Caldarelli G.; Puliga M.; Gabrielli A.

    2012-01-01

    We present a novel method to reconstruct complex network from partial information. We assume to know the links only for a subset of the nodes and to know some non-topological quantity (fitness) characterising every node. The missing links are generated on the basis of the latter quan- tity according to a fitness model calibrated on the subset of nodes for which links are known. We measure the quality of the reconstruction of several topological properties, such as the network density and the ...

  10. Bootstrapping topology and systemic risk of complex network using the fitness model

    CERN Document Server

    Musmeci, Nicoló; Caldarelli, Guido; Puliga, Michelangelo; Gabrielli, Andrea

    2012-01-01

    We present a novel method to reconstruct complex network from partial information. We assume to know the links only for a subset of the nodes and to know some non-topological quantity (fitness) characterising every node. The missing links are generated on the basis of the latter quan- tity according to a fitness model calibrated on the subset of nodes for which links are known. We measure the quality of the reconstruction of several topological properties, such as the network density and the degree distri- bution as a function of the size of the initial subset of nodes. Moreover, we also study the resilience of the network to distress propagation. We first test the method on ensembles of synthetic networks generated with the Exponential Random Graph model which allows to apply common tools from statistical mechanics. We then test it on the empirical case of the World Trade Web. In both cases, we find that a subset of 10 % of nodes is enough to reconstruct the main features of the network along with its resili...

  11. Search Models: Who Does the Looking?

    Science.gov (United States)

    Duffield, Judith A.

    1996-01-01

    Describes two search models for school libraries. Models include searches defined by the student but conducted by a trained searcher, and student-conducted searches which teach search skills. Decisions about which model (or combination) to use should be based on the available resources and the purposes for conducting the search. (AEF)

  12. Temperature Corrected Bootstrap Algorithm

    Science.gov (United States)

    Comiso, Joey C.; Zwally, H. Jay

    1997-01-01

    A temperature corrected Bootstrap Algorithm has been developed using Nimbus-7 Scanning Multichannel Microwave Radiometer data in preparation to the upcoming AMSR instrument aboard ADEOS and EOS-PM. The procedure first calculates the effective surface emissivity using emissivities of ice and water at 6 GHz and a mixing formulation that utilizes ice concentrations derived using the current Bootstrap algorithm but using brightness temperatures from 6 GHz and 37 GHz channels. These effective emissivities are then used to calculate surface ice which in turn are used to convert the 18 GHz and 37 GHz brightness temperatures to emissivities. Ice concentrations are then derived using the same technique as with the Bootstrap algorithm but using emissivities instead of brightness temperatures. The results show significant improvement in the area where ice temperature is expected to vary considerably such as near the continental areas in the Antarctic, where the ice temperature is colder than average, and in marginal ice zones.

  13. A Search Model of Discouragement

    DEFF Research Database (Denmark)

    Rosholm, Michael; Toomet, Ott

    Discouragement is a process occurring during an unemployment spell. As the spell prolongs, an individual gradually realises that the returns to search can no longer outweigh search costs, and hence she may eventually leave the labour force. This is analysed theoretically in a framework of unemplo...... to analyse theoretically the impact of changes in unemployment insurance and social assistance benefits, and we conduct some simulation exercises based on a calibrated model....... of unemployed search. We construct a search model, which is stationary from the point of view of the individual, but which has nonstationary features. Namely, the unemployed worker is occasionally hit by shocks leading to a decline in job offer arrival rates. These shocks can be due to stigmatisation...... or to psychological consequences of unemployement affecting search effectiveness. This model enables us to analyse the issue of discouragement, as the returns to search will gradually decline. Even so, the model is actually stationary from the point of view of the individual, which implies that many interesting...

  14. Scalar-Vector Bootstrap

    CERN Document Server

    Rejon-Barrera, Fernando

    2015-01-01

    We work out all of the details required for implementation of the conformal bootstrap program applied to the four-point function of two scalars and two vectors in an abstract conformal field theory in arbitrary dimension. This includes a review of which tensor structures make appearances, a construction of the projectors onto the required mixed symmetry representations, and a computation of the conformal blocks for all possible operators which can be exchanged. These blocks are presented as differential operators acting upon the previously known scalar conformal blocks. Finally, we set up the bootstrap equations which implement crossing symmetry. Special attention is given to the case of conserved vectors, where several simplifications occur.

  15. Introduction to the Bootstrap World

    OpenAIRE

    Boos, Dennis D.

    2003-01-01

    The bootstrap has made a fundamental impact on how we carry out statistical inference in problems without analytic solutions. This fact is illustrated with examples and comments that emphasize the parametric bootstrap and hypothesis testing.

  16. A PARAMETRIC BOOTSTRAP USING THE FIRST FOURMOMENTS OF THE RESIDUALS

    OpenAIRE

    Pierre-Eric Treyens

    2007-01-01

    We consider linear regression models and we suppose that disturbances are either Gaussian or non Gaussian. Until now, within the framework of the bootstrap, we thought that the error in rejection probability (ERP) had the same rate of convergence with the parametric bootstrap or the nonparametric bootstrap. For linear data generating processes (DGP) we show in this paper that this assertion is false if skewness and/or kurtosis coefficients of the distribution of the disturbances are nonnull. ...

  17. Generalized bootstrap for estimating equations

    OpenAIRE

    Chatterjee, Snigdhansu; Bose, Arup

    2005-01-01

    We introduce a generalized bootstrap technique for estimators obtained by solving estimating equations. Some special cases of this generalized bootstrap are the classical bootstrap of Efron, the delete-d jackknife and variations of the Bayesian bootstrap. The use of the proposed technique is discussed in some examples. Distributional consistency of the method is established and an asymptotic representation of the resampling variance estimator is obtained.

  18. Conceptual Models for Search Engines

    Science.gov (United States)

    Hendry, D. G.; Efthimiadis, E. N.

    Search engines have entered popular culture. They touch people in diverse private and public settings and thus heighten the importance of such important social matters as information privacy and control, censorship, and equitable access. To fully benefit from search engines and to participate in debate about their merits, people necessarily appeal to their understandings for how they function. In this chapter we examine the conceptual understandings that people have of search engines by performing a content analysis on the sketches that 200 undergraduate and graduate students drew when asked to draw a sketch of how a search engine works. Analysis of the sketches reveals a diverse range of conceptual approaches, metaphors, representations, and misconceptions. On the whole, the conceptual models articulated by these students are simplistic. However, students with higher levels of academic achievement sketched more complete models. This research calls attention to the importance of improving students' technical knowledge of how search engines work so they can be better equipped to develop and advocate policies for how search engines should be embedded in, and restricted from, various private and public information settings.

  19. The Local Fractional Bootstrap

    DEFF Research Database (Denmark)

    Bennedsen, Mikkel; Hounyo, Ulrich; Lunde, Asger;

    We introduce a bootstrap procedure for high-frequency statistics of Brownian semistationary processes. More specifically, we focus on a hypothesis test on the roughness of sample paths of Brownian semistationary processes, which uses an estimator based on a ratio of realized power variations. Our...... to two empirical data sets: we assess the roughness of a time series of high-frequency asset prices and we test the validity of Kolmogorov's scaling law in atmospheric turbulence data.......We introduce a bootstrap procedure for high-frequency statistics of Brownian semistationary processes. More specifically, we focus on a hypothesis test on the roughness of sample paths of Brownian semistationary processes, which uses an estimator based on a ratio of realized power variations. Our...... and in simulations we observe that the bootstrap-based hypothesis test provides considerable finite-sample improvements over an existing test that is based on a central limit theorem. This is important when studying the roughness properties of time series data; we illustrate this by applying the bootstrap method...

  20. Phenotypic stability via ammi model with bootstrap re-sampling Estabilidade fenotípica através da reamostragem “bootstrap” no modelo AMMI

    Directory of Open Access Journals (Sweden)

    Osmir José Lavoranti

    2010-06-01

    Full Text Available Reliable evaluation of the stability of genotypes and environment is of prime concern to plant breeders, but the lack of a comprehensive analysis of the structure of the GE interaction has been a stumbling block to the recommendation of varieties. The Additive Main Effects and Multiplicative Interaction (AMMI Model currently offers the good approach to interpretation and  understanding of the GE interaction but lacks a way of assessing the stability of its estimates. The present contribution proposes the use of bootstrap resampling
    in the AMMI Model, and applies it to obtain both a graphical and a numerical analysis of the phenotypic
    stability of 20 Eucalyptus grandis progenies from Australia that were planted in seven environments in the Southern and Southeastern regions of Brazil. The results showed distinct behaviors of genotypes and
    environments and the genotype x environment interaction was significant (p value < 0.01. The bootstrap coefficient of stability based on the squared Mahalanobis distance of the scores showed that genotypes and environments can be differentiated in terms of their stabilities. Graphical analysis of the AMMI biplot provided a better understanding of the interpretation of phenotypic stability. The proposed AMMI bootstrap eliminated the uncertainties regarding the identification of low scores in traditional analyses.As posições críticas dos estatísticos, que atuam em programas de melhoramento genético, referem-se à falta de uma análise criteriosa da estrutura da interação do genótipo com o ambiente (GE como um dos principais problemas para a recomendação de cultivares. A metodologia AMMI (additive main effects and multiplicative interaction analysis propõe ser mais eficiente que as análises usuais na interpretação e compreensão da interação GE, entretanto, à dificuldade de se interpretar a interação quando há baixa explicação do primeiro componente principal; à dificuldade de

  1. Bootstrap Percolation on Random Geometric Graphs

    CERN Document Server

    Bradonjić, Milan

    2012-01-01

    Bootstrap percolation has been used effectively to model phenomena as diverse as emergence of magnetism in materials, spread of infection, diffusion of software viruses in computer networks, adoption of new technologies, and emergence of collective action and cultural fads in human societies. It is defined on an (arbitrary) network of interacting agents whose state is determined by the state of their neighbors according to a threshold rule. In a typical setting, bootstrap percolation starts by random and independent "activation" of nodes with a fixed probability $p$, followed by a deterministic process for additional activations based on the density of active nodes in each neighborhood ($\\th$ activated nodes). Here, we study bootstrap percolation on random geometric graphs in the regime when the latter are (almost surely) connected. Random geometric graphs provide an appropriate model in settings where the neighborhood structure of each node is determined by geographical distance, as in wireless {\\it ad hoc} ...

  2. IMPLEMENTASI METODE BOOTSTRAP DALAM INFERENSI TITIK-TITIK BIPLOT AMMI MODEL AMMI CAMPURAN (MIXED AMMI (Studi Kasus: Menduga Stabilitas Genotipe Padi

    Directory of Open Access Journals (Sweden)

    NI PUTU AYU DINITA TRISNAYANTI

    2015-06-01

    Full Text Available In this research bootstrap methods are used to determine the points inference of biplot figures on the analysis of AMMI. If the environmental factors are assumed to be random factors, then Mixed AMMI is used as a model of analysis.  In the analysis of the stabilit, the main components score interaction used are KUI1 and KUI2. The purpose of this study is to determine the Biplot figures based on two scores these are KUI with the greatest diversity of Mixed AMMI models and the points inference by using the bootstrap method. The stable genotypes obtained from biplot AMMI2 are G1, G5, and G6. Based on points inference of each genotype, G1 and G5 can be regarded as the most stable genotype. This is because the distribution of G1 and G5 are the closest to the center point (0,0 and both of them have  a small radius.

  3. Bootstrap Tests and Confidence Regions for Functions of a Covariance Matrix

    OpenAIRE

    Beran, Rudolf; Srivastava, Muni S.

    1985-01-01

    Bootstrap tests and confidence regions for functions of the population covariance matrix have the desired asymptotic levels, provided model restrictions, such as multiple eigenvalues in the covariance matrix, are taken into account in designing the bootstrap algorithm.

  4. Unbiased Estimates of Variance Components with Bootstrap Procedures

    Science.gov (United States)

    Brennan, Robert L.

    2007-01-01

    This article provides general procedures for obtaining unbiased estimates of variance components for any random-model balanced design under any bootstrap sampling plan, with the focus on designs of the type typically used in generalizability theory. The results reported here are particularly helpful when the bootstrap is used to estimate standard…

  5. A nonparametric hypothesis test via the Bootstrap resampling

    OpenAIRE

    Temel, Tugrul

    2011-01-01

    This paper adapts an already existing nonparametric hypothesis test to the bootstrap framework. The test utilizes the nonparametric kernel regression method to estimate a measure of distance between the models stated under the null hypothesis. The bootstraped version of the test allows to approximate errors involved in the asymptotic hypothesis test. The paper also develops a Mathematica Code for the test algorithm.

  6. BOOTSTRAPPING FOR EXTRACTING RELATIONS FROM LARGE CORPORA

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A new approach of relation extraction is described in this paper. It adopts a bootstrapping model with a novel iteration strategy, which generates more precise examples of specific relation. Compared with previous methods, the proposed method has three main advantages: first, it needs less manual intervention; second, more abundant and reasonable information are introduced to represent a relation pattern; third, it reduces the risk of circular dependency occurrence in bootstrapping. Scalable evaluation methodology and metrics are developed for our task with comparable techniques over TianWang 100G corpus. The experimental results show that it can get 90% precision and have excellent expansibility.

  7. The wild tapered block bootstrap

    DEFF Research Database (Denmark)

    Hounyo, Ulrich

    In this paper, a new resampling procedure, called the wild tapered block bootstrap, is introduced as a means of calculating standard errors of estimators and constructing confidence regions for parameters based on dependent heterogeneous data. The method consists in tapering each overlapping block...... of the series first, the applying the standard wild bootstrap for independent and heteroscedastic distrbuted observations to overlapping tapered blocks in an appropriate way. Its perserves the favorable bias and mean squared error properties of the tapered block bootstrap, which is the state-of-the-art block......-order asymptotic validity of the tapered block bootstrap as well as the wild tapered block bootstrap approximation to the actual distribution of the sample mean is also established when data are assumed to satisfy a near epoch dependent condition. The consistency of the bootstrap variance estimator for the sample...

  8. Detrending bootstrap unit root tests

    OpenAIRE

    Smeekes, S.

    2009-01-01

    The role of detrending in bootstrap unit root tests is investigated. When bootstrapping, detrending must not only be done for the construction of the test statistic, but also in the first step of the bootstrap algorithm. It is argued that the two points should be treated separately. Asymptotic validity of sieve bootstrap ADF unit root tests is shown for test statistics based on full sample and recursive OLS and GLS detrending. It is also shown that the detrending method in the first step of t...

  9. Towards Bootstrapping QED$_3$

    CERN Document Server

    Chester, Shai M

    2016-01-01

    We initiate the conformal bootstrap study of Quantum Electrodynamics in $2+1$ space-time dimensions (QED$_{3}$) with $N$ flavors of charged fermions by focusing on the 4-point function of four monopole operators with the lowest unit of topological charge. We obtain upper bounds on the scaling dimension of the doubly-charged monopole operator, with and without assuming other gaps in the operator spectrum. Intriguingly, we find a (gap-dependent) kink in these bounds that comes reasonably close to the large $N$ extrapolation of the scaling dimensions of the singly-charged and doubly-charged monopole operators down to $N=4$ and $N=6$.

  10. Discussion on the paper "Analyzing short time series data from periodically fluctuating rodent populations by threshold models: A nearest block bootstrap approach"

    Institute of Scientific and Technical Information of China (English)

    HALL Peter

    2009-01-01

    @@ This is a very attractive article. It combines fascinating new methodology with a most interesting dataset, and a highly motivating presentation. However, despite the many opportunities for discussion, I am going to confine attention to the issue of the block bootstrap, ingeniously developed in this paper into the nearest block bootstrap.

  11. On sieve bootstrap prediction intervals.

    OpenAIRE

    Andrés M. Alonso; Peña, Daniel; Romo Urroz, Juan

    2003-01-01

    In this paper we consider a sieve bootstrap method for constructing nonparametric prediction intervals for a general class of linear processes. We show that the sieve bootstrap provides consistent estimators of the conditional distribution of future values given the observed data.

  12. Ultrafast Approximation for Phylogenetic Bootstrap

    NARCIS (Netherlands)

    Bui Quang Minh, [No Value; Nguyen, Thi; von Haeseler, Arndt

    2013-01-01

    Nonparametric bootstrap has been a widely used tool in phylogenetic analysis to assess the clade support of phylogenetic trees. However, with the rapidly growing amount of data, this task remains a computational bottleneck. Recently, approximation methods such as the RAxML rapid bootstrap (RBS) and

  13. Explorations in Statistics: the Bootstrap

    Science.gov (United States)

    Curran-Everett, Douglas

    2009-01-01

    Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This fourth installment of Explorations in Statistics explores the bootstrap. The bootstrap gives us an empirical approach to estimate the theoretical variability among possible values of a sample statistic such as the…

  14. Second Thoughts on the Bootstrap

    OpenAIRE

    Efron, Bradley

    2003-01-01

    This brief review article is appearing in the issue of Statistical Science that marks the 25th anniversary of the bootstrap. It concerns some of the theoretical and methodological aspects of the bootstrap and how they might influence future work in statistics.

  15. Applications of the Fast Double Bootstrap

    OpenAIRE

    MacKinnon, James G.

    2006-01-01

    The fast double bootstrap, or FDB, is a procedure for calculating bootstrap P values that is much more computationally efficient than the double bootstrap itself. In many cases, it can provide more accurate results than ordinary bootstrap tests. For the fast double bootstrap to be valid, the test statistic must be asymptotically independent of the random parts of the bootstrap data generating process. This paper presents simulation evidence on the performance of FDB tests in three cases of in...

  16. Breakdown Point Theory for Implied Probability Bootstrap

    OpenAIRE

    Lorenzo Camponovo; Taisuke Otsu

    2011-01-01

    This paper studies robustness of bootstrap inference methods under moment conditions. In particular, we compare the uniform weight and implied probability bootstraps by analyzing behaviors of the bootstrap quantiles when outliers take arbitrarily large values, and derive the breakdown points for those bootstrap quantiles. The breakdown point properties characterize the situation where the implied probability bootstrap is more robust than the uniform weight bootstrap against outliers. Simulati...

  17. Automatic bootstrapping and tracking of object contours.

    Science.gov (United States)

    Chiverton, John; Xie, Xianghua; Mirmehdi, Majid

    2012-03-01

    A new fully automatic object tracking and segmentation framework is proposed. The framework consists of a motion-based bootstrapping algorithm concurrent to a shape-based active contour. The shape-based active contour uses finite shape memory that is automatically and continuously built from both the bootstrap process and the active-contour object tracker. A scheme is proposed to ensure that the finite shape memory is continuously updated but forgets unnecessary information. Two new ways of automatically extracting shape information from image data given a region of interest are also proposed. Results demonstrate that the bootstrapping stage provides important motion and shape information to the object tracker. This information is found to be essential for good (fully automatic) initialization of the active contour. Further results also demonstrate convergence properties of the content of the finite shape memory and similar object tracking performance in comparison with an object tracker with unlimited shape memory. Tests with an active contour using a fixed-shape prior also demonstrate superior performance for the proposed bootstrapped finite-shape-memory framework and similar performance when compared with a recently proposed active contour that uses an alternative online learning model. PMID:21908256

  18. Modular Bootstrap Revisited

    CERN Document Server

    Collier, Scott; Yin, Xi

    2016-01-01

    We constrain the spectrum of two-dimensional unitary, compact conformal field theories with central charge c > 1 using modular bootstrap. Upper bounds on the gap in the dimension of primary operators of any spin, as well as in the dimension of scalar primaries, are computed numerically as functions of the central charge using semi-definite programming. Our bounds refine those of Hellerman and Friedan-Keller, and are in some cases saturated by known CFTs. In particular, we show that unitary CFTs with c < 8 must admit relevant deformations, and that a nontrivial bound on the gap of scalar primaries exists for c < 25. We also study bounds on the dimension gap in the presence of twist gaps, bounds on the degeneracy of operators, and demonstrate how "extremal spectra" which maximize the degeneracy at the gap can be determined numerically.

  19. Bootstrap consistency for general semiparametric M-estimation

    KAUST Repository

    Cheng, Guang

    2010-10-01

    Consider M-estimation in a semiparametric model that is characterized by a Euclidean parameter of interest and an infinite-dimensional nuisance parameter. As a general purpose approach to statistical inferences, the bootstrap has found wide applications in semiparametric M-estimation and, because of its simplicity, provides an attractive alternative to the inference approach based on the asymptotic distribution theory. The purpose of this paper is to provide theoretical justifications for the use of bootstrap as a semiparametric inferential tool. We show that, under general conditions, the bootstrap is asymptotically consistent in estimating the distribution of the M-estimate of Euclidean parameter; that is, the bootstrap distribution asymptotically imitates the distribution of the M-estimate. We also show that the bootstrap confidence set has the asymptotically correct coverage probability. These general onclusions hold, in particular, when the nuisance parameter is not estimable at root-n rate, and apply to a broad class of bootstrap methods with exchangeable ootstrap weights. This paper provides a first general theoretical study of the bootstrap in semiparametric models. © Institute of Mathematical Statistics, 2010.

  20. A Novel Personalized Web Search Model

    Institute of Scientific and Technical Information of China (English)

    ZHU Zhengyu; XU Jingqiu; TIAN Yunyan; REN Xiang

    2007-01-01

    A novel personalized Web search model is proposed.The new system, as a middleware between a user and a Web search engine, is set up on the client machine. It can learn a user's preference implicitly and then generate the user profile automatically. When the user inputs query keywords, the system can automatically generate a few personalized expansion words by computing the term-term associations according to the current user profile, and then these words together with the query keywords are submitted to a popular search engine such as Yahoo or Google.These expansion words help to express accurately the user's search intention. The new Web search model can make a common search engine personalized, that is, the search engine can return different search results to different users who input the same keywords. The experimental results show the feasibility and applicability of the presented work.

  1. Genetic search feature selection for affective modeling

    DEFF Research Database (Denmark)

    Martínez, Héctor P.; Yannakakis, Georgios N.

    2010-01-01

    Automatic feature selection is a critical step towards the generation of successful computational models of affect. This paper presents a genetic search-based feature selection method which is developed as a global-search algorithm for improving the accuracy of the affective models built. The met......Automatic feature selection is a critical step towards the generation of successful computational models of affect. This paper presents a genetic search-based feature selection method which is developed as a global-search algorithm for improving the accuracy of the affective models built...

  2. Bootstrapping Realized Multivariate Volatility Measures.

    OpenAIRE

    Donovon, Prosper; Goncalves, Silvia; Meddahi, Nour

    2013-01-01

    We study bootstrap methods for statistics that are a function of multivariate high frequency returns such as realized regression coefficients and realized covariances and correlations. For these measures of covariation, the Monte Carlo simulation results of Barndorff-Nielsen and Shephard (2004) show that finite sample distortions associated with their feasible asymptotic theory approach may arise if sampling is not too frequent. This motivates our use of the bootstrap as an altern...

  3. Bootstrapping Deep Lexical Resources: Resources for Courses

    CERN Document Server

    Baldwin, Timothy

    2007-01-01

    We propose a range of deep lexical acquisition methods which make use of morphological, syntactic and ontological language resources to model word similarity and bootstrap from a seed lexicon. The different methods are deployed in learning lexical items for a precision grammar, and shown to each have strengths and weaknesses over different word classes. A particular focus of this paper is the relative accessibility of different language resource types, and predicted ``bang for the buck'' associated with each in deep lexical acquisition applications.

  4. TASI Lectures on the Conformal Bootstrap

    CERN Document Server

    Simmons-Duffin, David

    2016-01-01

    These notes are from courses given at TASI and the Advanced Strings School in summer 2015. Starting from principles of quantum field theory and the assumption of a traceless stress tensor, we develop the basics of conformal field theory, including conformal Ward identities, radial quantization, reflection positivity, the operator product expansion, and conformal blocks. We end with an introduction to numerical bootstrap methods, focusing on the 2d and 3d Ising models.

  5. Spectrum of local boundary operators from boundary form factor bootstrap

    CERN Document Server

    Szots, M

    2007-01-01

    Using the recently introduced boundary form factor bootstrap equations, we map the complete space of their solutions for the boundary version of the scaling Lee-Yang model and sinh-Gordon theory. We show that the complete space of solutions, graded by the ultraviolet behaviour of the form factors can be brought into correspondence with the spectrum of local boundary operators expected from boundary conformal field theory, which is a major evidence for the correctness of the boundary form factor bootstrap framework.

  6. Bootstrapped Multinomial Logistic Regression on Apnea Detection Using ECG Data

    OpenAIRE

    Sanabila, Hadaiq R.; Fanany, Mohamad Ivan; Jatmiko, Wisnu; Arymurthy, Aniati Murni

    2010-01-01

    In designing a classification system, one of the most important considerations is how optimal the classifier will adapt and give best generalization when it is given data from unknown model distribution. Unlike linear regression, logistic regression has no simple formula to assess its generalization ability. In such cases, bootstrapping offers an advantage over analytical methods thanks to its simplicity. This paper presents an analysis of bootstrapped multinomial logistic regression appli...

  7. The Talent Search Model of Gifted Identification

    Science.gov (United States)

    Assouline, Susan G.; Lupkowski-Shoplik, Ann

    2012-01-01

    The Talent Search model, founded at Johns Hopkins University by Dr. Julian C. Stanley, is fundamentally an above-level testing program. This simplistic description belies the enduring impact that the Talent Search model has had on the lives of hundreds of thousands of gifted students as well as their parents and teachers. In this article, we…

  8. Proposal of a bootstrap procedure using measures of influence in non-linear regression models with outliers - doi: 10.4025/actascitechnol.v36i1.17564

    Directory of Open Access Journals (Sweden)

    Larissa Ribeiro de Andrade

    2014-01-01

    Full Text Available The bootstrap method is generally performed by presupposing that each sample unit would show the same probability of being re-sampled. However, when a sample with outliers is taken into account, the empirical distribution generated by this method may be influenced, or rather, it may not accurately represent the original sample. Current study proposes a bootstrap algorithm that allows the use of measures of influence in the calculation of re-sampling probabilities. The method was reproduced in simulation scenarios taking into account the logistic growth curve model and the CovRatio measurement to evaluate the impact of an influential observation in the determinacy of the matrix of the co-variance of parameter estimates. In most cases, bias estimates were reduced. Consequently, the method is suitable to be used in non-linear models and allows the researcher to apply other measures for better bias reductions.

  9. Double-bootstrap methods that use a single double-bootstrap simulation

    OpenAIRE

    Chang, Jinyuan; Hall, Peter

    2014-01-01

    We show that, when the double bootstrap is used to improve performance of bootstrap methods for bias correction, techniques based on using a single double-bootstrap sample for each single-bootstrap sample can be particularly effective. In particular, they produce third-order accuracy for much less computational expense than is required by conventional double-bootstrap methods. However, this improved level of performance is not available for the single double-bootstrap methods that have been s...

  10. Enhancing Expert Search Through Query Modeling

    NARCIS (Netherlands)

    Serdyukov, Pavel; Chernov, Sergey; Nejdl, Wolfgang

    2007-01-01

    An expert finding is a very common task among enterprise search activities, while its usual retrieval performance is far from the quality of the Web search. Query modeling helps to improve traditional document retrieval, so we propose to apply it in a new setting. We adopt a general framework of lan

  11. Security bootstrapping model of key pre-sharing in MANET%MANET环境下的密钥预共享安全引导模型

    Institute of Scientific and Technical Information of China (English)

    吴畏; 彭茜; 冯力; 张剑

    2011-01-01

    Key pre-sharing model based on one-way hash function and (t,n) threshold schema of La- grange polynomial group was proposed to implement the security bootstrapping in mobile Ad hoc net- works (MANET) environment. This model involved following two phases, including the pre-sharing keys based on one way hash function and'I Lagrange interpolation polynomial group, and recovering the secure key based on the digital signature of threshold schema. The one way hash approach can effec- tively prevent the splitted key pieces in a key pool from being exposed. The digital signature of threshold schema also has advantages to detect and block the DoS attack and other malicious fraudu- lent behaviors during the processes of key reconstruction and recovery. The experiments of simulated environment were performed to validate the approach on the performance of successful establishing se- cure link, computation complexity, the security of bootstrapping process, the capability of network recovery from compromised nodes, and the network scale etc. The simulated experimental results show that this approach can harden the security of MANET environment with better performance.%提出了一种移动自组织网络(MANET)环境下基于单向哈希函数和拉格朗日插值多项式组的(t,n)门限方案的随机密钥预共享安全引导模型,该安全引导过程分为基于单向哈希函数和拉格朗日插值多项式组的密钥预共享安全引导过程以及基于门限数字签名的密钥安全恢复协议2个部分.引导模型采用了单向哈希函数,使得每个密钥分片的子密钥难以被暴露,同时将门限数字签名机制引入到了密钥恢复协议的安全引导过程中,有效检测和防止了在密钥恢复或重组过程中的欺骗行为以及DoS攻击.实验验证从安全引导成功的性能、模型计算复杂度、节点被俘后的网络恢复能力、引导过程安全性、网络对各种路由攻击的抵抗力以及

  12. Exploring Contextual Models in Chemical Patent Search

    Science.gov (United States)

    Urbain, Jay; Frieder, Ophir

    We explore the development of probabilistic retrieval models for integrating term statistics with entity search using multiple levels of document context to improve the performance of chemical patent search. A distributed indexing model was developed to enable efficient named entity search and aggregation of term statistics at multiple levels of patent structure including individual words, sentences, claims, descriptions, abstracts, and titles. The system can be scaled to an arbitrary number of compute instances in a cloud computing environment to support concurrent indexing and query processing operations on large patent collections.

  13. Bootstrap bias-adjusted GMM estimators

    OpenAIRE

    Ramalho, Joaquim J.S.

    2005-01-01

    The ability of six alternative bootstrap methods to reduce the bias of GMM parameter estimates is examined in an instrumental variable framework using Monte Carlo analysis. Promising results were found for the two bootstrap estimators suggested in the paper.

  14. Analytical bootstrap methods for censored data

    OpenAIRE

    Alan D. Hutson

    2002-01-01

    Analytic bootstrap estimators for the moments of survival quantities are derived. By using these expressions recommendations can be made as to the appropriateness of bootstrap estimation under censored data conditions.

  15. A PARAMETRIC BOOTSTRAP USING THE FIRST FOUR
    MOMENTS OF THE RESIDUALS

    OpenAIRE

    Treyens, Pierre-Eric

    2007-01-01

    We consider linear regression models and we suppose that disturbances are either Gaussian or non Gaussian. Until now, within the framework of the bootstrap, we thought that the error in rejection probability (ERP) had the same rate of convergence with the parametric bootstrap or the nonparametric bootstrap. For linear data generating processes (DGP) we show in this paper that this assertion is false if skewness and/or kurtosis coefficients of the distribution of the disturbances are nonnull. ...

  16. Accidental Symmetries and the Conformal Bootstrap

    CERN Document Server

    Chester, Shai M; Iliesiu, Luca V; Klebanov, Igor R; Pufu, Silviu S; Yacoby, Ran

    2015-01-01

    We study an ${\\cal N} = 2$ supersymmetric generalization of the three-dimensional critical $O(N)$ vector model that is described by $N+1$ chiral superfields with superpotential $W = g_1 X \\sum_i Z_i^2 + g_2 X^3$. By combining the tools of the conformal bootstrap with results obtained through supersymmetric localization, we argue that this model exhibits a symmetry enhancement at the infrared superconformal fixed point due to $g_2$ flowing to zero. This example is special in that the existence of an infrared fixed point with $g_1,g_2\

  17. Simplified Models for LHC New Physics Searches

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Daniele; /SLAC; Arkani-Hamed, Nima; /Princeton, Inst. Advanced Study; Arora, Sanjay; /Rutgers U., Piscataway; Bai, Yang; /SLAC; Baumgart, Matthew; /Johns Hopkins U.; Berger, Joshua; /Cornell U., Phys. Dept.; Buckley, Matthew; /Fermilab; Butler, Bart; /SLAC; Chang, Spencer; /Oregon U. /UC, Davis; Cheng, Hsin-Chia; /UC, Davis; Cheung, Clifford; /UC, Berkeley; Chivukula, R.Sekhar; /Michigan State U.; Cho, Won Sang; /Tokyo U.; Cotta, Randy; /SLAC; D' Alfonso, Mariarosaria; /UC, Santa Barbara; El Hedri, Sonia; /SLAC; Essig, Rouven, (ed.); /SLAC; Evans, Jared A.; /UC, Davis; Fitzpatrick, Liam; /Boston U.; Fox, Patrick; /Fermilab; Franceschini, Roberto; /LPHE, Lausanne /Pittsburgh U. /Argonne /Northwestern U. /Rutgers U., Piscataway /Rutgers U., Piscataway /Carleton U. /CERN /UC, Davis /Wisconsin U., Madison /SLAC /SLAC /SLAC /Rutgers U., Piscataway /Syracuse U. /SLAC /SLAC /Boston U. /Rutgers U., Piscataway /Seoul Natl. U. /Tohoku U. /UC, Santa Barbara /Korea Inst. Advanced Study, Seoul /Harvard U., Phys. Dept. /Michigan U. /Wisconsin U., Madison /Princeton U. /UC, Santa Barbara /Wisconsin U., Madison /Michigan U. /UC, Davis /SUNY, Stony Brook /TRIUMF; /more authors..

    2012-06-01

    This document proposes a collection of simplified models relevant to the design of new-physics searches at the LHC and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the 'Topologies for Early LHC Searches' workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first {approx} 50-500 pb{sup -1} of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.

  18. Improving the Reliability of Bootstrap Tests

    OpenAIRE

    Russell Davidson; MacKinnon, James G.

    2000-01-01

    We first propose procedures for estimating the rejection probabilities for bootstrap tests in Monte Carlo experiments without actually computing a bootstrap test for each replication. These procedures are only about twice as expensive as estimating rejection probabilities for asymptotic tersts. We then propose procedures for computing modified bootstrap P values that will often be more accurate than ordinary ones. These procedures are closely related to the double bootstrap, but they are far ...

  19. The bootstrap and edgeworth expansion

    CERN Document Server

    Hall, Peter

    1992-01-01

    This monograph addresses two quite different topics, in the belief that each can shed light on the other. Firstly, it lays the foundation for a particular view of the bootstrap. Secondly, it gives an account of Edgeworth expansion. Chapter 1 is about the bootstrap, witih almost no mention of Edgeworth expansion; Chapter 2 is about Edgeworth expansion, with scarcely a word about the bootstrap; and Chapters 3 and 4 bring these two themes together, using Edgeworth expansion to explore and develop the properites of the bootstrap. The book is aimed a a graduate level audience who has some exposure to the methods of theoretical statistics. However, technical details are delayed until the last chapter (entitled "Details of Mathematical Rogour"), and so a mathematically able reader without knowledge of the rigorous theory of probability will have no trouble understanding the first four-fifths of the book. The book simultaneously fills two gaps in the literature; it provides a very readable graduate level account of t...

  20. Simplified Models for LHC New Physics Searches

    CERN Document Server

    Alves, Daniele; Arora, Sanjay; Bai, Yang; Baumgart, Matthew; Berger, Joshua; Buckley, Matthew; Butler, Bart; Chang, Spencer; Cheng, Hsin-Chia; Cheung, Clifford; Chivukula, R.Sekhar; Cho, Won Sang; Cotta, Randy; D'Alfonso, Mariarosaria; El Hedri, Sonia; Essig, Rouven; Evans, Jared A.; Fitzpatrick, Liam; Fox, Patrick; Franceschini, Roberto; Freitas, Ayres; Gainer, James S.; Gershtein, Yuri; Gray, Richard; Gregoire, Thomas; Gripaios, Ben; Gunion, Jack; Han, Tao; Haas, Andy; Hansson, Per; Hewett, JoAnne; Hits, Dmitry; Hubisz, Jay; Izaguirre, Eder; Kaplan, Jared; Katz, Emanuel; Kilic, Can; Kim, Hyung-Do; Kitano, Ryuichiro; Koay, Sue Ann; Ko, Pyungwon; Krohn, David; Kuflik, Eric; Lewis, Ian; Lisanti, Mariangela; Liu, Tao; Liu, Zhen; Lu, Ran; Luty, Markus; Meade, Patrick; Morrissey, David; Mrenna, Stephen; Nojiri, Mihoko; Okui, Takemichi; Padhi, Sanjay; Papucci, Michele; Park, Michael; Park, Myeonghun; Perelstein, Maxim; Peskin, Michael; Phalen, Daniel; Rehermann, Keith; Rentala, Vikram; Roy, Tuhin; Ruderman, Joshua T.; Sanz, Veronica; Schmaltz, Martin; Schnetzer, Stephen; Schuster, Philip; Schwaller, Pedro; Schwartz, Matthew D.; Schwartzman, Ariel; Shao, Jing; Shelton, Jessie; Shih, David; Shu, Jing; Silverstein, Daniel; Simmons, Elizabeth; Somalwar, Sunil; Spannowsky, Michael; Spethmann, Christian; Strassler, Matthew; Su, Shufang; Tait, Tim; Thomas, Brooks; Thomas, Scott; Toro, Natalia; Volansky, Tomer; Wacker, Jay; Waltenberger, Wolfgang; Yavin, Itay; Yu, Felix; Zhao, Yue; Zurek, Kathryn

    2012-01-01

    This document proposes a collection of simplified models relevant to the design of new-physics searches at the LHC and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the "Topologies for Early LHC Searches" workshop, held at SLAC in September of 2010, the purpose of which was to develop a...

  1. On the Asymptotic Accuracy of Efron's Bootstrap

    OpenAIRE

    Singh, Kesar

    1981-01-01

    In the non-lattice case it is shown that the bootstrap approximation of the distribution of the standardized sample mean is asymptotically more accurate than approximation by the limiting normal distribution. The exact convergence rate of the bootstrap approximation of the distributions of sample quantiles is obtained. A few other convergence rates regarding the bootstrap method are also studied.

  2. Coefficient Omega Bootstrap Confidence Intervals: Nonnormal Distributions

    Science.gov (United States)

    Padilla, Miguel A.; Divers, Jasmin

    2013-01-01

    The performance of the normal theory bootstrap (NTB), the percentile bootstrap (PB), and the bias-corrected and accelerated (BCa) bootstrap confidence intervals (CIs) for coefficient omega was assessed through a Monte Carlo simulation under conditions not previously investigated. Of particular interests were nonnormal Likert-type and binary items.…

  3. Query and document models for enterprise search

    NARCIS (Netherlands)

    K. Balog; K. Hofmann; W. Weerkamp; M. de Rijke

    2007-01-01

    We describe our participation in the TREC 2007 Enterprise track and detail our language modeling-based approaches. For document search, our focus was on estimating a mixture model using a standard web collection, and on constructing query models by employing blind relevance feedback and using the ex

  4. Financial bootstrapping : Motivation and usage of bootstrapping methods among SMEs in the tourism sector

    OpenAIRE

    Feti, Andreea; Dudele, Aiga

    2012-01-01

    Bootstrapping plays a vital role in the life of small and medium-sized enter-prises. By providing a large variety of financing alternatives bootstrapping ensures the existence of entrepreneurship, even though, too less attention is paid to bootstrapping in the specific literature. Therefore, the master thesis strives to eliminate the gaps in the theory by bringing new insights in the field of bootstrapping.The purpose of the master thesis is to investigate the usage of boot-strapping methods ...

  5. Bootstrapped efficiency measures of oil blocks in Angola

    International Nuclear Information System (INIS)

    This paper investigates the technical efficiency of Angola oil blocks over the period 2002-2007. A double bootstrap data envelopment analysis (DEA) model is adopted composed in the first stage of a DEA-variable returns to scale (VRS) model and then followed in the second stage by a bootstrapped truncated regression. Results showed that on average, the technical efficiency has fluctuated over the period of study, but deep and ultradeep oil blocks have generally maintained a consistent efficiency level. Policy implications are derived.

  6. Bootstrapping N=2 chiral correlators

    Energy Technology Data Exchange (ETDEWEB)

    Lemos, Madalena [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Liendo, Pedro [Humboldt-Univ. Berlin (Germany). IMIP

    2015-12-15

    We apply the numerical bootstrap program to chiral operators in four-dimensional N=2 SCFTs. In the first part of this work we study four-point functions in which all fields have the same conformal dimension. We give special emphasis to bootstrapping a specific theory: the simplest Argyres-Douglas fixed point with no flavor symmetry. In the second part we generalize our setup and consider correlators of fields with unequal dimension. This is an example of a mixed correlator and allows us to probe new regions in the parameter space of N=2 SCFTs. In particular, our results put constraints on relations in the Coulomb branch chiral ring and on the curvature of the Zamolodchikov metric.

  7. On a generalized bootstrap principle

    International Nuclear Information System (INIS)

    The S-matrices for non-simply-laced affine Toda field theories are considered in the context of a generalized bootstrap principle. The S-matrices, and in particular their poles, depend on a parameter whose range lies between the Coxeter numbers of dual pairs of the corresponding non-simply-laced algebras. It is proposed that only odd order poles in the physical strip with positive coefficients throughout this range should participate in the bootstrap. All other singularities have an explanation in principle in terms of a generalized Coleman-Thun mechanism. Besides the S-matrices introduced by Delius, Grisaru and Zanon, the missing case (F4(1), e6(2)), is also considered and provides many interesting examples of pole generation. (author)

  8. Bootstrap Current in Spherical Tokamaks

    Institute of Scientific and Technical Information of China (English)

    王中天; 王龙

    2003-01-01

    Variational principle for the neoclassical theory has been developed by including amomentum restoring term in the electron-electron collisional operator, which gives an additionalfree parameter maximizing the heat production rate. All transport coefficients are obtained in-cluding the bootstrap current. The essential feature of the study is that the aspect ratio affects thefunction of the electron-electron collision operator through a geometrical factor. When the aspectratio approaches to unity, the fraction of circulating particles goes to zero and the contribution toparticle flux from the electron-electron collision vanishes. The resulting diffusion coefficient is inrough agreement with Hazeltine. When the aspect ratio approaches to infinity, the results are inagreement with Rosenbluth. The formalism gives the two extreme cases a connection. The theoryis particularly important for the calculation of bootstrap current in spherical tokamaks and thepresent tokamaks, in which the square root of the inverse aspect ratio, in general, is not small.

  9. Adaptive wavelet detection of transients using the bootstrap

    Science.gov (United States)

    Hewer, Gary A.; Kuo, Wei; Peterson, Lawrence A.

    1996-03-01

    A Daubechies wavelet-based bootstrap detection strategy based on the research of Carmona was applied to a set of test signals. The detector was a function of the d-scales. The adaptive detection statistics were derived using Efron's bootstrap methodology, which relieved us from having to make parametric assumptions about the underlying noise and offered a method of overcoming the constraints of modeling the detector statistics. The test set of signals used to evaluate the Daubechies/bootstrap pulse detector were generated with a Hewlett-Packard Fast Agile Signal Simulator (FASS). These video pulses, with varying signal-to-noise ratios (SNRs), included unmodulated, linear chirp, and Barker phase-code modulations baseband (IF) video pulses mixed with additive white Gaussian noise. Simulated examples illustrating the bootstrap methodology are presented, along with a complete set of constant false alarm rate (CFAR) detection statistics for the test signals. The CFAR curves clearly show that the wavelet bootstrap can adaptively detect transient pulses at low SNRs.

  10. A bootstrap estimation scheme for chemical compositional data with nondetects

    Science.gov (United States)

    Palarea-Albaladejo, J; Martín-Fernández, J.A; Olea, Ricardo A.

    2014-01-01

    The bootstrap method is commonly used to estimate the distribution of estimators and their associated uncertainty when explicit analytic expressions are not available or are difficult to obtain. It has been widely applied in environmental and geochemical studies, where the data generated often represent parts of whole, typically chemical concentrations. This kind of constrained data is generically called compositional data, and they require specialised statistical methods to properly account for their particular covariance structure. On the other hand, it is not unusual in practice that those data contain labels denoting nondetects, that is, concentrations falling below detection limits. Nondetects impede the implementation of the bootstrap and represent an additional source of uncertainty that must be taken into account. In this work, a bootstrap scheme is devised that handles nondetects by adding an imputation step within the resampling process and conveniently propagates their associated uncertainly. In doing so, it considers the constrained relationships between chemical concentrations originated from their compositional nature. Bootstrap estimates using a range of imputation methods, including new stochastic proposals, are compared across scenarios of increasing difficulty. They are formulated to meet compositional principles following the log-ratio approach, and an adjustment is introduced in the multivariate case to deal with nonclosed samples. Results suggest that nondetect bootstrap based on model-based imputation is generally preferable. A robust approach based on isometric log-ratio transformations appears to be particularly suited in this context. Computer routines in the R statistical programming language are provided. 

  11. Conformal Bootstrap in Embedding Space

    CERN Document Server

    Fortin, Jean-François

    2016-01-01

    It is shown how to obtain conformal blocks from embedding space with the help of the operator product expansion. The minimal conformal block originates from scalar exchange in a four-point correlation functions of four scalars. All remaining conformal blocks are simple derivatives of the minimal conformal block. With the help of the orthogonality properties of the conformal blocks, the analytic conformal bootstrap can be implemented directly in embedding space, leading to a Jacobi-like definition of conformal field theories.

  12. Conformal bootstrap in embedding space

    Science.gov (United States)

    Fortin, Jean-François; Skiba, Witold

    2016-05-01

    It is shown how to obtain conformal blocks from embedding space with the help of the operator product expansion. The minimal conformal block originates from scalar exchange in a four-point correlation function of four scalars. All remaining conformal blocks are simple derivatives of the minimal conformal block. With the help of the orthogonality properties of the conformal blocks, the analytic conformal bootstrap can be implemented directly in embedding space, leading to a Jacobi-like definition of conformal field theories.

  13. Bootstrapping High Dimensional Time Series

    OpenAIRE

    Zhang, Xianyang; Cheng, Guang

    2014-01-01

    This article studies bootstrap inference for high dimensional weakly dependent time series in a general framework of approximately linear statistics. The following high dimensional applications are covered: (1) uniform confidence band for mean vector; (2) specification testing on the second order property of time series such as white noise testing and bandedness testing of covariance matrix; (3) specification testing on the spectral property of time series. In theory, we first derive a Gaussi...

  14. Modified Bootstrap Sensitometry In Radiography

    Science.gov (United States)

    Bednarek, Daniel R.; Rudin, Stephen

    1981-04-01

    A new modified bootstrap approach to sensitometry is presented which provides H and D curves that show almost exact agreement with those obtained using conventional methods. Two bootstrap techniques are described; both involve a combination of inverse-square and stepped-wedge modulation of the radiation field and provide intensity-scale sensitometric curves as appropriate for medical radiography. H and D curves obtained with these modified techniques are compared with those obtained for screen-film combinations using inverse-square sensitometry as well as with those obtained for direct x-ray film using time-scale sensitometry. The stepped wedge of the Wisconsin X-Ray Test Cassette was used in the bootstrap approach since it provides sufficient exposure latitude to encompass the useful density range of medical x-ray film. This approach makes radiographic sensitometry quick and convenient, allowing accurate characteristic curves to be obtained for any screen-film cassette using standard diagnostic x-ray equipment.

  15. Metastability Thresholds for Anisotropic Bootstrap Percolation in Three Dimensions

    NARCIS (Netherlands)

    Van Enter, A.C.D.; Fey, A.

    2012-01-01

    In this paper we analyze several anisotropic bootstrap percolation models in three dimensions. We present the order of magnitude for the metastability thresholds for a fairly general class of models. In our proofs, we use an adaptation of the technique of dimensional reduction. We find that the orde

  16. Metastability thresholds for anisotropic bootstrap percolation in three dimensions

    NARCIS (Netherlands)

    Van Enter, A.C.D.; Fey, A.

    2012-01-01

    In this paper we analyze several anisotropic bootstrap percolation models in three dimensions. We present the order of magnitude for the metastability thresholds for a fairly general class of models. In our proofs, we use an adaptation of the technique of dimensional reduction. We find that the orde

  17. An Empirical Model of Employed Search, Unemployed Search, and Nonsearch.

    Science.gov (United States)

    Kahn, Lawrence M.; Low, Stuart A.

    1984-01-01

    The 1969-1971 National Longitudinal Surveys data on young men were used to study the employed worker's choice among employed search, unemployed search, and not searching for a new job. The principal results are that current wages, seniority, collective bargaining coverage, employment outside construction, and employment by government are each…

  18. The search for stable prognostic models in multiple imputed data sets

    Directory of Open Access Journals (Sweden)

    de Vet Henrica CW

    2010-09-01

    Full Text Available Abstract Background In prognostic studies model instability and missing data can be troubling factors. Proposed methods for handling these situations are bootstrapping (B and Multiple imputation (MI. The authors examined the influence of these methods on model composition. Methods Models were constructed using a cohort of 587 patients consulting between January 2001 and January 2003 with a shoulder problem in general practice in the Netherlands (the Dutch Shoulder Study. Outcome measures were persistent shoulder disability and persistent shoulder pain. Potential predictors included socio-demographic variables, characteristics of the pain problem, physical activity and psychosocial factors. Model composition and performance (calibration and discrimination were assessed for models using a complete case analysis, MI, bootstrapping or both MI and bootstrapping. Results Results showed that model composition varied between models as a result of how missing data was handled and that bootstrapping provided additional information on the stability of the selected prognostic model. Conclusion In prognostic modeling missing data needs to be handled by MI and bootstrap model selection is advised in order to provide information on model stability.

  19. Simplified Models for Exotic BSM Searches

    CERN Document Server

    Heisig, Jan; Quertenmont, Loic

    2015-01-01

    Simplified models are a successful way of interpreting current LHC searches for models beyond the standard model (BSM). So far simplified models have focused on topologies featuring a missing transverse energy (MET) signature. However, in some BSM theories other, more exotic, signatures occur. If a charged particle becomes long-lived on collider time scales - as it is the case in parts of the SUSY parameter space - it leads to a very distinct signature. We present an extension of the computer package SModelS which includes simplified models for heavy stable charged particles (HSCP). As a physical application we investigate the CMSSM stau co-annihilation strip containing long-lived staus, which presents a potential solution to the Lithium problem. Applying both MET and HSCP constraints we show that, for low values of $\\tan\\beta$, all this region of parameter space either violates Dark Matter constraints or is excluded by LHC searches.

  20. Bootstrapping Time Dilation Decoherence

    CERN Document Server

    Gooding, Cisco

    2015-01-01

    We present a general relativistic model of a spherical shell of matter with a perfect fluid on its surface coupled to an internal oscillator, which generalizes a model recently introduced by the authors to construct a self-gravitating interferometer [1]. The internal oscillator evolution is defined with respect to the local proper time of the shell, allowing the oscillator to serve as a local clock that ticks differently depending on the shell's position and momentum. A Hamiltonian reduction is performed on the system, and an approximate quantum description is given to the reduced phase space. If we focus only on the external dynamics, we must trace out the clock degree of freedom, and this results in a form of intrinsic decoherence that shares some features with a proposed "universal" decoherence mechanism attributed to gravitational time dilation [2]. We show that the proposed decoherence remains present in the (gravity-free) limit of flat spacetime, indicating that the effect can be attributed entirely to ...

  1. Generalized Bootstrap Method for Assessment of Uncertainty in Semivariogram Inference

    Science.gov (United States)

    Olea, R.A.; Pardo-Iguzquiza, E.

    2011-01-01

    The semivariogram and its related function, the covariance, play a central role in classical geostatistics for modeling the average continuity of spatially correlated attributes. Whereas all methods are formulated in terms of the true semivariogram, in practice what can be used are estimated semivariograms and models based on samples. A generalized form of the bootstrap method to properly model spatially correlated data is used to advance knowledge about the reliability of empirical semivariograms and semivariogram models based on a single sample. Among several methods available to generate spatially correlated resamples, we selected a method based on the LU decomposition and used several examples to illustrate the approach. The first one is a synthetic, isotropic, exhaustive sample following a normal distribution, the second example is also a synthetic but following a non-Gaussian random field, and a third empirical sample consists of actual raingauge measurements. Results show wider confidence intervals than those found previously by others with inadequate application of the bootstrap. Also, even for the Gaussian example, distributions for estimated semivariogram values and model parameters are positively skewed. In this sense, bootstrap percentile confidence intervals, which are not centered around the empirical semivariogram and do not require distributional assumptions for its construction, provide an achieved coverage similar to the nominal coverage. The latter cannot be achieved by symmetrical confidence intervals based on the standard error, regardless if the standard error is estimated from a parametric equation or from bootstrap. ?? 2010 International Association for Mathematical Geosciences.

  2. Theoretical comparisons of block bootstrap methods

    OpenAIRE

    Lahiri, S. N.

    1999-01-01

    In this paper, we compare the asymptotic behavior of some common block bootstrap methods based on nonrandom as well as random block lengths. It is shown that, asymptotically, bootstrap estimators derived using any of the methods considered in the paper have the same amount of bias to the first order. However, the variances of these bootstrap estimators may be different even in the first order. Expansions for the bias, the variance and the mean-squared error of different bloc...

  3. Investigations of dipole localization accuracy in MEG using the bootstrap.

    Science.gov (United States)

    Darvas, F; Rautiainen, M; Pantazis, D; Baillet, S; Benali, H; Mosher, J C; Garnero, L; Leahy, R M

    2005-04-01

    We describe the use of the nonparametric bootstrap to investigate the accuracy of current dipole localization from magnetoencephalography (MEG) studies of event-related neural activity. The bootstrap is well suited to the analysis of event-related MEG data since the experiments are repeated tens or even hundreds of times and averaged to achieve acceptable signal-to-noise ratios (SNRs). The set of repetitions or epochs can be viewed as a set of independent realizations of the brain's response to the experiment. Bootstrap resamples can be generated by sampling with replacement from these epochs and averaging. In this study, we applied the bootstrap resampling technique to MEG data from somatotopic experimental and simulated data. Four fingers of the right and left hand of a healthy subject were electrically stimulated, and about 400 trials per stimulation were recorded and averaged in order to measure the somatotopic mapping of the fingers in the S1 area of the brain. Based on single-trial recordings for each finger we performed 5000 bootstrap resamples. We reconstructed dipoles from these resampled averages using the Recursively Applied and Projected (RAP)-MUSIC source localization algorithm. We also performed a simulation for two dipolar sources with overlapping time courses embedded in realistic background brain activity generated using the prestimulus segments of the somatotopic data. To find correspondences between multiple sources in each bootstrap, sample dipoles with similar time series and forward fields were assumed to represent the same source. These dipoles were then clustered by a Gaussian Mixture Model (GMM) clustering algorithm using their combined normalized time series and topographies as feature vectors. The mean and standard deviation of the dipole position and the dipole time series in each cluster were computed to provide estimates of the accuracy of the reconstructed source locations and time series. PMID:15784414

  4. A bootstrapped neural network model applied to prediction of the biodegradation rate of reactive Black 5 dye - doi: 10.4025/actascitechnol.v35i3.16210

    Directory of Open Access Journals (Sweden)

    Kleber Rogério Moreira Prado

    2013-06-01

    Full Text Available Current essay forwards a biodegradation model of a dye, used in the textile industry, based on a neural network propped by bootstrap remodeling. Bootstrapped neural network is set to generate estimates that are close to results obtained in an intrinsic experience in which a chemical process is applied. Pseudomonas oleovorans was used in the biodegradation of reactive Black 5. Results show a brief comparison between the information estimated by the proposed approach and the experimental data, with a coefficient of correlation between real and predicted values for a more than 0.99 biodegradation rate. Dye concentration and the solution’s pH failed to interfere in biodegradation index rates. A value above 90% of dye biodegradation was achieved between 1.000 and 1.841 mL 10 mL-1 of microorganism concentration and between 1.000 and 2.000 g 100 mL-1 of glucose concentration within the experimental conditions under analysis.   

  5. Bootstrap percolation on spatial networks

    Science.gov (United States)

    Gao, Jian; Zhou, Tao; Hu, Yanqing

    2015-10-01

    Bootstrap percolation is a general representation of some networked activation process, which has found applications in explaining many important social phenomena, such as the propagation of information. Inspired by some recent findings on spatial structure of online social networks, here we study bootstrap percolation on undirected spatial networks, with the probability density function of long-range links’ lengths being a power law with tunable exponent. Setting the size of the giant active component as the order parameter, we find a parameter-dependent critical value for the power-law exponent, above which there is a double phase transition, mixed of a second-order phase transition and a hybrid phase transition with two varying critical points, otherwise there is only a second-order phase transition. We further find a parameter-independent critical value around -1, about which the two critical points for the double phase transition are almost constant. To our surprise, this critical value -1 is just equal or very close to the values of many real online social networks, including LiveJournal, HP Labs email network, Belgian mobile phone network, etc. This work helps us in better understanding the self-organization of spatial structure of online social networks, in terms of the effective function for information spreading.

  6. Testing optimality in job search models

    OpenAIRE

    John W. Schindler

    2001-01-01

    This paper uses Bayesian techniques to compare three definitions of optimality for the basic job search model: the standard income-maximizing definition, an approximation to the standard definition, and a simple alternative. The important role of prior choice in these comparisons is illustrated. Using natural conjugate priors to represent hypothetical samples of data, we find that the simple alternative is preferred to the standard definition of optimality. However, using priors constructed f...

  7. Finger Search in the Implicit Model

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Nielsen, Jesper Asbjørn Sindahl; Truelsen, Jakob

    2012-01-01

    the finger to another element is Ω(q− 1(logn)), where t is the rank distance between the query element and the finger. We present an optimal implicit static structure matching this lower bound. We furthermore present a near optimal implicit dynamic structure supporting search, change-finger, insert......We address the problem of creating a dictionary with the finger search property in the strict implicit model, where no information is stored between operations, except the array of elements. We show that for any implicit dictionary supporting finger searches in q(t) = Ω(logt) time, the time to move......, and delete in times $\\mathcal{O}(q(t))$, $\\mathcal{O}(q^{-1}(\\log n)\\log n)$, $\\mathcal{O}(\\log n)$, and $\\mathcal{O}(\\log n)$, respectively, for any q(t) = Ω(logt). Finally we show that the search operation must take Ω(logn) time for the special case where the finger is always changed to the element...

  8. A Bayesian Bootstrap for a Finite Population

    OpenAIRE

    Lo, Albert Y.

    1988-01-01

    A Bayesian bootstrap for a finite population is introduced; its small-sample distributional properties are discussed and compared with those of the frequentist bootstrap for a finite population. It is also shown that the two are first-order asymptotically equivalent.

  9. Bootstrapping Phylogenetic Trees: Theory and Methods

    OpenAIRE

    Holmes, Susan

    2003-01-01

    This is a survey of the use of the bootstrap in the area of systematic and evolutionary biology. I present the current usage by biologists of the bootstrap as a tool both for making inferences and for evaluating robustness, and propose a framework for thinking about these problems in terms of mathematical statistics.

  10. Coefficient Alpha Bootstrap Confidence Interval under Nonnormality

    Science.gov (United States)

    Padilla, Miguel A.; Divers, Jasmin; Newton, Matthew

    2012-01-01

    Three different bootstrap methods for estimating confidence intervals (CIs) for coefficient alpha were investigated. In addition, the bootstrap methods were compared with the most promising coefficient alpha CI estimation methods reported in the literature. The CI methods were assessed through a Monte Carlo simulation utilizing conditions…

  11. A comparison of four different block bootstrap methods

    OpenAIRE

    Boris Radovanov; Aleksandra Marcikić

    2014-01-01

    The paper contains a description of four different block bootstrap methods, i.e., non-overlapping block bootstrap, overlapping block bootstrap (moving block bootstrap), stationary block bootstrap and subsampling. Furthermore, the basic goal of this paper is to quantify relative efficiency of each mentioned block bootstrap procedure and then to compare those methods. To achieve the goal, we measure mean square errors of estimation variance returns. The returns are calculated from 1250 daily ob...

  12. Advertising for attention in a consumer search model

    NARCIS (Netherlands)

    Haan, M.A.; Moraga González, J.L.

    2011-01-01

    We model the idea that when consumers search for products, they first visit the firm whose advertising is most salient. The gains a firm derives from being visited early increase in search costs, so equilibrium advertising increases as search costs rise. As a result, higher search costs may decrease

  13. A neural network based reputation bootstrapping approach for service selection

    Science.gov (United States)

    Wu, Quanwang; Zhu, Qingsheng; Li, Peng

    2015-10-01

    With the concept of service-oriented computing becoming widely accepted in enterprise application integration, more and more computing resources are encapsulated as services and published online. Reputation mechanism has been studied to establish trust on prior unknown services. One of the limitations of current reputation mechanisms is that they cannot assess the reputation of newly deployed services as no record of their previous behaviours exists. Most of the current bootstrapping approaches merely assign default reputation values to newcomers. However, by this kind of methods, either newcomers or existing services will be favoured. In this paper, we present a novel reputation bootstrapping approach, where correlations between features and performance of existing services are learned through an artificial neural network (ANN) and they are then generalised to establish a tentative reputation when evaluating new and unknown services. Reputations of services published previously by the same provider are also incorporated for reputation bootstrapping if available. The proposed reputation bootstrapping approach is seamlessly embedded into an existing reputation model and implemented in the extended service-oriented architecture. Empirical studies of the proposed approach are shown at last.

  14. Bootstrap-Based Regularization for Low-Rank Matrix Estimation

    OpenAIRE

    Josse, Julie; Wager, Stefan

    2014-01-01

    We develop a flexible framework for low-rank matrix estimation that allows us to transform noise models into regularization schemes via a simple bootstrap algorithm. Effectively, our procedure seeks an autoencoding basis for the observed matrix that is stable with respect to the specified noise model; we call the resulting procedure a stable autoencoder. In the simplest case, with an isotropic noise model, our method is equivalent to a classical singular value shrinkage estimator. For non-iso...

  15. The N=2 superconformal bootstrap

    Science.gov (United States)

    Beem, Christopher; Lemos, Madalena; Liendo, Pedro; Rastelli, Leonardo; van Rees, Balt C.

    2016-03-01

    In this work we initiate the conformal bootstrap program for N=2 super-conformal field theories in four dimensions. We promote an abstract operator-algebraic viewpoint in order to unify the description of Lagrangian and non-Lagrangian theories, and formulate various conjectures concerning the landscape of theories. We analyze in detail the four-point functions of flavor symmetry current multiplets and of N=2 chiral operators. For both correlation functions we review the solution of the superconformal Ward identities and describe their superconformal block decompositions. This provides the foundation for an extensive numerical analysis discussed in the second half of the paper. We find a large number of constraints for operator dimensions, OPE coefficients, and central charges that must hold for any N=2 superconformal field theory.

  16. Bootstrapping Object Coreferencing on the Semantic Web

    Institute of Scientific and Technical Information of China (English)

    Wei Hu; Yu-Zhong Qu; Xing-Zhi Sun

    2011-01-01

    An object on the Semantic Web is likely to be denoted with several URIs by different parties.Object coreferencing is a process to identify "equivalent" URIs of objects for achieving a better Data Web.In this paper,we propose a bootstrapping approach for object coreferencing on the Semantic Web.For an object URI,we firstly establish a kernel that consists of semantically equivalent URIs from the same-as,(inverse) functional properties and (max-)cardinalities,and then extend the kernel with respect to the textual descriptions (e.g.,labels and local names) of URIs.We also propose a trustworthiness-based method to rank the coreferent URIs in the kernel as well as a similarity-based method for ranking the URIs in the extension of the kernel.We implement the proposed approach,called ObjectCoref,on a large-scale dataset that contains 76 million URIs collected by the Falcons search engine until 2008.The evaluation on precision,relative recall and response time demonstrates the feasibility of our approach.Additionally,we apply the proposed approach to investigate the popularity of the URI alias phenomenon on the current Semantic Web.

  17. Recent CMS searches for exotic phenomena beyond the Standard Model

    CERN Document Server

    Wulsin, H Wells

    2015-01-01

    The results of several recent CMS searches for exotic phenomena beyond the Standard Model are presented in this talk. Two searches look for new physics in a final state with a vector boson and missing transverse energy. Three searches target massive resonances decaying to a Higgs boson and a vector boson. Finally, preliminary results are presented for the first CMS search for exotic phenomena using $\\sqrt{s} = 13$ TeV data, the search for dijet resonances.

  18. Discrimination and Skill Differences in an Equilibrium Search Model

    NARCIS (Netherlands)

    Bowlus, Audra J.; Eckstein, Zvi

    1998-01-01

    In this paper we analyze an equilibrium search model with threesources for wage andunemployment differentials among workers with the same (observed) human capital but different appearance (race): unobserved productivity (skill), search intensities and discrimination (Becker 1957)due to an appearanc

  19. Search for symmetries beyond the Standard Model with ATLAS

    CERN Document Server

    Tal Hod, Noam; The ATLAS collaboration

    2015-01-01

    Searches for new physics beyond the Standard Model (SM) at the LHC are mainly driven by two approaches: a signature-based search where one looks for a deviation from the SM prediction in event yield or kinematic properties, and a more theory-oriented approach where the search is designed to look for specific signatures/topologies predicted by certain beyond standard model (BSM ) scenarios. Extensive searches for such signatures have been performed in ATLAS at LHC Run 1 in the context of Supersymmetry, Extended Gauge models, Technicolor, Little Higgs, Extra Dimensions, Left-Right symmetric models, and many other BSM scenarios. Highlights from these searches are presented.

  20. Improving the Reliability of Bootstrap Tests with the Fast Double Bootstrap

    OpenAIRE

    Davidson, Russell; MacKinnon, James

    2006-01-01

    Two procedures are proposed for estimating the rejection probabilities of bootstrap tests in Monte Carlo experiments without actually computing a bootstrap test for each replication. These procedures are only about twice as expensive (per replication) as estimating rejection probabilities for asymptotic tests. Then a new procedure is proposed for computing bootstrap P values that will often be more accurate than ordinary ones. This “fast double bootstrap” is closely related to the double boot...

  1. iDESWEB: Frameworks CSS: Bootstrap

    OpenAIRE

    Yuste Torregrosa, Álvaro; Luján Mora, Sergio

    2012-01-01

    Framework CSS (herramientas y pautas), frameworks más famosos (BluePrint, 960 Grid System, YUI), Twitter Bootstrap, ejemplo de botones, ejemplo de uso de la rejilla. Sitio web del curso: http://idesweb.es/

  2. Bootstrapping Reflective Systems: The Case of Pharo

    OpenAIRE

    Polito, Guillermo; Ducasse, Stéphane; Fabresse, Luc; Bouraqadi, Noury; Van Ryseghem, Benjamin

    2014-01-01

    Bootstrapping is a technique commonly known by its usage in language definition by the introduction of a compiler written in the same language it compiles. This process is important to understand and modify the definition of a given language using the same language, taking benefit of the abstractions and expression power it provides. A bootstrap, then, supports the evolution of a language. However, the infrastructure of reflective systems like Smalltalk includes, in addition to a compiler, an...

  3. Theoretical Comparison of Bootstrap Confidence Intervals

    OpenAIRE

    Hall, Peter

    1988-01-01

    We develop a unified framework within which many commonly used bootstrap critical points and confidence intervals may be discussed and compared. In all, seven different bootstrap methods are examined, each being usable in both parametric and nonparametric contexts. Emphasis is on the way in which the methods cope with first- and second-order departures from normality. Percentile-$t$ and accelerated bias-correction emerge as the most promising of existing techniques. Certain other methods are ...

  4. Bootstrap Prediction Intervals in Non-Parametric Regression with Applications to Anomaly Detection

    Science.gov (United States)

    Kumar, Sricharan; Srivistava, Ashok N.

    2012-01-01

    Prediction intervals provide a measure of the probable interval in which the outputs of a regression model can be expected to occur. Subsequently, these prediction intervals can be used to determine if the observed output is anomalous or not, conditioned on the input. In this paper, a procedure for determining prediction intervals for outputs of nonparametric regression models using bootstrap methods is proposed. Bootstrap methods allow for a non-parametric approach to computing prediction intervals with no specific assumptions about the sampling distribution of the noise or the data. The asymptotic fidelity of the proposed prediction intervals is theoretically proved. Subsequently, the validity of the bootstrap based prediction intervals is illustrated via simulations. Finally, the bootstrap prediction intervals are applied to the problem of anomaly detection on aviation data.

  5. 'Bootstrap' charging of surfaces composed of multiple materials

    Science.gov (United States)

    Stannard, P. R.; Katz, I.; Parks, D. E.

    1981-01-01

    The paper examines the charging of a checkerboard array of two materials, only one of which tends to acquire a negative potential alone, using the NASA Charging Analyzer Program (NASCAP). The influence of the charging material's field causes the otherwise 'non-charging' material to acquire a negative potential due to the suppression of its secondary emission ('bootstrap' charging). The NASCAP predictions for the equilibrium potential difference between the two materials are compared to results based on an analytical model.

  6. Higgs Critical Exponents and Conformal Bootstrap in Four Dimensions

    DEFF Research Database (Denmark)

    Antipin, Oleg; Mølgaard, Esben; Sannino, Francesco

    2015-01-01

    We investigate relevant properties of composite operators emerging in nonsupersymmetric, four-dimensional gauge-Yukawa theories with interacting conformal fixed points within a precise framework. The theories investigated in this work are structurally similar to the standard model of particle int...... bootstrap results are then compared to precise four dimensional conformal field theoretical results. To accomplish this, it was necessary to calculate explicitly the crossing symmetry relations for the global symmetry group SU($N$)$\\times$SU($N$)....

  7. Spectrum of local boundary operators from boundary form factor bootstrap

    OpenAIRE

    Szots, M.; Takacs, G.

    2007-01-01

    Using the recently introduced boundary form factor bootstrap equations, we map the complete space of their solutions for the boundary version of the scaling Lee-Yang model and sinh-Gordon theory. We show that the complete space of solutions, graded by the ultraviolet behaviour of the form factors can be brought into correspondence with the spectrum of local boundary operators expected from boundary conformal field theory, which is a major evidence for the correctness of the boundary form fact...

  8. Study and Integrate Bootstrap 3 for OpixManager

    OpenAIRE

    Tapani, Zhejia

    2010-01-01

    ABSTRACT This bachelor thesis is about how to study and integrate Bootstrap 3 into OpixManager. The purpose is to improve user interface of OpixManager application. OpixManager is constructed by using CodeIgniter and Model-View-Controller (MVC) framework. OpixManager application is for project management. It includes staff augmentation, customer management, report management and so on. It is to support both scrum and traditional software development process. There are two major parts...

  9. A conformal bootstrap approach to critical percolation in two dimensions

    CERN Document Server

    Picco, Marco; Santachiara, Raoul

    2016-01-01

    We study four-point functions of critical percolation in two dimensions, and more generally of the Potts model. We propose an exact ansatz for the spectrum: an infinite, discrete and non-diagonal combination of representations of the Virasoro algebra. Based on this ansatz, we compute four-point functions using a numerical conformal bootstrap approach. The results agree with Monte-Carlo computations of connectivities of random clusters.

  10. The Bootstrap of Mean for Dependent Heterogeneous Arrays.

    OpenAIRE

    GONÇALVES, Silvia; White, Halbert

    2001-01-01

    Presently, conditions ensuring the validity of bootstrap methods for the sample mean of (possibly heterogeneous) near epoch dependent (NED) functions of mixing processes are unknown. Here we establish the validity of the bootstrap in this context, extending the applicability of bootstrap methods to a class of processes broadly relevant for applications in economics and finance. Our results apply to two block bootstrap methods: the moving blocks bootstrap of Künsch ( 989) and Liu and Singh ( 9...

  11. Top partner searches and Composite Higgs models

    Energy Technology Data Exchange (ETDEWEB)

    Matsedonskyi, Oleksii [DESY Hamburg (Germany); Panico, Giuliano [Barcelona Univ. Autonoma (Spain). IFAE; Wulyer, Andrea [Padova Univ. (Italy). Dipt. di Fisica e Astronomia; INFN, Padova (Italy)

    2015-12-15

    Colored fermionic partners of the top quark are well-known signatures of the Composite Higgs scenario and for this reason they have been and will be subject of an intensive experimental study at the LHC. Performing an assessment of the theoretical implications of this experimental effort is the goal of the present paper. We proceed by analyzing a set of simple benchmark models, characterized by simple two-dimensional parameter spaces where the results of the searches are conveniently visualized and their impact quantified. We only draw exclusion contours, in the hypothesis of no signal, but of course our formalism could equally well be used to report discoveries in a theoretically useful format.

  12. Top partner searches and Composite Higgs models

    International Nuclear Information System (INIS)

    Colored fermionic partners of the top quark are well-known signatures of the Composite Higgs scenario and for this reason they have been and will be subject of an intensive experimental study at the LHC. Performing an assessment of the theoretical implications of this experimental effort is the goal of the present paper. We proceed by analyzing a set of simple benchmark models, characterized by simple two-dimensional parameter spaces where the results of the searches are conveniently visualized and their impact quantified. We only draw exclusion contours, in the hypothesis of no signal, but of course our formalism could equally well be used to report discoveries in a theoretically useful format.

  13. Conformal bootstrap: non-perturbative QFT's under siege

    CERN Document Server

    CERN. Geneva

    2016-01-01

    [Exceptionally in Council Chamber] Originally formulated in the 70's, the conformal bootstrap is the ambitious idea that one can use internal consistency conditions to carve out, and eventually solve, the space of conformal field theories. In this talk I will review recent developments in the field which have boosted this program to a new level. I will present a method to extract quantitative informations in strongly-interacting theories, such as 3D Ising, O(N) vector model and even systems without a Lagrangian formulation. I will explain how these techniques have led to the world record determination of several critical exponents. Finally, I will review exact analytical results obtained using bootstrap techniques.

  14. Quantum bootstrapping via compressed quantum Hamiltonian learning

    International Nuclear Information System (INIS)

    A major problem facing the development of quantum computers or large scale quantum simulators is that general methods for characterizing and controlling are intractable. We provide a new approach to this problem that uses small quantum simulators to efficiently characterize and learn control models for larger devices. Our protocol achieves this by using Bayesian inference in concert with Lieb–Robinson bounds and interactive quantum learning methods to achieve compressed simulations for characterization. We also show that the Lieb–Robinson velocity is epistemic for our protocol, meaning that information propagates at a rate that depends on the uncertainty in the system Hamiltonian. We illustrate the efficiency of our bootstrapping protocol by showing numerically that an 8 qubit Ising model simulator can be used to calibrate and control a 50 qubit Ising simulator while using only about 750 kilobits of experimental data. Finally, we provide upper bounds for the Fisher information that show that the number of experiments needed to characterize a system rapidly diverges as the duration of the experiments used in the characterization shrinks, which motivates the use of methods such as ours that do not require short evolution times. (fast track communication)

  15. Semantic Web Based Efficient Search Using Ontology and Mathematical Model

    Directory of Open Access Journals (Sweden)

    K.Palaniammal

    2014-01-01

    Full Text Available The semantic web is the forthcoming technology in the world of search engine. It becomes mainly focused towards the search which is more meaningful rather than the syntactic search prevailing now. This proposed work concerns about the semantic search with respect to the educational domain. In this paper, we propose semantic web based efficient search using ontology and mathematical model that takes into account the misleading, unmatched kind of service information, lack of relevant domain knowledge and the wrong service queries. To solve these issues in this framework is designed to make three major contributions, which are ontology knowledge base, Natural Language Processing (NLP techniques and search model. Ontology knowledge base is to store domain specific service ontologies and service description entity (SDE metadata. The search model is to retrieve SDE metadata as efficient for Education lenders, which include mathematical model. The Natural language processing techniques for spell-check and synonym based search. The results are retrieved and stored in an ontology, which in terms prevents the data redundancy. The results are more accurate to search, sensitive to spell check and synonymous context. This paper reduces the user’s time and complexity in finding for the correct results of his/her search text and our model provides more accurate results. A series of experiments are conducted in order to respectively evaluate the mechanism and the employed mathematical model.

  16. Truncatable bootstrap equations in algebraic form and critical surface exponents

    CERN Document Server

    Gliozzi, Ferdinando

    2016-01-01

    We describe examples of drastic truncations of conformal bootstrap equations encoding much more information than that obtained by a direct numerical approach. A three-term truncation of the four point function of a free scalar in any space dimensions provides algebraic identities among conformal block derivatives which generate the exact spectrum of the infinitely many primary operators contributing to it. In boundary conformal field theories, we point out that the appearance of free parameters in the solutions of bootstrap equations is not an artifact of truncations, rather it reflects a physical property of permeable conformal interfaces which are described by the same equations. Surface transitions correspond to isolated points in the parameter space. We are able to locate them in the case of 3d Ising model, thanks to a useful algebraic form of 3d boundary bootstrap equations. It turns out that the low-lying spectra of the surface operators in the ordinary and the special transitions of 3d Ising model form...

  17. Projection of bootstrap current in the ITER with standard type I ELMy H-mode and steady state scenarios

    Directory of Open Access Journals (Sweden)

    Thawatchai Onjun

    2012-02-01

    Full Text Available The investigation of bootstrap current formation in ITER is carried out using BALDUR integrated predictive modelingcode. The combination of Mixed B/gB anomalous transport model and NLCASS module together with the pedestal model isused in BALDUR code to simulate the time evolution of temperature, density, and plasma current profiles. It was found inthe simulations that without the presence of ITB, a minimal fraction of bootstrap current (as well as low fusion performancewas achieved. The enhancement due to ITB depends sensitively on the strength of toroidal velocity. A sensitivity study wasalso carried out to optimize the bootstrap current fraction and plasma performance. It was found that the bootstrap currentfraction slightly improved; while the plasma performance greatly improved with increasing of NBI power or pedestal temperature.On the other hand, higher impurity concentration resulted in a significant degradation of fusion performance, buta smaller degradation in bootstrap current.

  18. RNA Structural Homology Search with a Succinct Stochastic Grammar Model

    Institute of Scientific and Technical Information of China (English)

    Ying-Lei Song; Ji-Zhen Zhao; Chun-Mei Liu; Kan Liu; Russell Malmberg; Li-Ming Cai

    2005-01-01

    An increasing number of structural homology search tools, mostly based on profile stochastic context-free grammars (SCFGs) have been recently developed for the non-coding RNA gene identification. SCFGs can include statistical biases that often occur in RNA sequences, necessary to profile specific RNA structures for structural homology search. In this paper, a succinct stochastic grammar model is introduced for RNA that has competitive search effectiveness. More importantly, the profiling model can be easily extended to include pseudoknots, structures that are beyond the capability of profile SCFGs. In addition, the model allows heuristics to be exploited, resulting in a significant speed-up for the CYK algorithm-based search.

  19. Necessary Condition for Emergent Symmetry from the Conformal Bootstrap

    Science.gov (United States)

    Nakayama, Yu; Ohtsuki, Tomoki

    2016-09-01

    We use the conformal bootstrap program to derive the necessary conditions for emergent symmetry enhancement from discrete symmetry (e.g., Zn ) to continuous symmetry [e.g., U (1 )] under the renormalization group flow. In three dimensions, in order for Z2 symmetry to be enhanced to U (1 ) symmetry, the conformal bootstrap program predicts that the scaling dimension of the order parameter field at the infrared conformal fixed point must satisfy Δ1>1.08 . We also obtain the similar necessary conditions for Z3 symmetry with Δ1>0.580 and Z4 symmetry with Δ1>0.504 from the simultaneous conformal bootstrap analysis of multiple four-point functions. As applications, we show that our necessary conditions impose severe constraints on the nature of the chiral phase transition in QCD, the deconfinement criticality in Néel valence bond solid transitions, and anisotropic deformations in critical O (n ) models. We prove that some fixed points proposed in the literature are unstable under the perturbation that cannot be forbidden by the discrete symmetry. In these situations, the second-order phase transition with enhanced symmetry cannot happen.

  20. Modeling User Behavior and Attention in Search

    Science.gov (United States)

    Huang, Jeff

    2013-01-01

    In Web search, query and click log data are easy to collect but they fail to capture user behaviors that do not lead to clicks. As search engines reach the limits inherent in click data and are hungry for more data in a competitive environment, mining cursor movements, hovering, and scrolling becomes important. This dissertation investigates how…

  1. Information Search Process Model: How Freshmen Begin Research.

    Science.gov (United States)

    Swain, Deborah E.

    1996-01-01

    Investigates Kuhlthau's Search Process Model for information seeking using two Freshmen English classes. Data showed that students followed the six stages Kuhlthau proposed and suggest extensions to the model, including changing the order of the tasks, iterating and combining steps, and revising search goals based on social and interpersonal…

  2. Model Specification Searches Using Ant Colony Optimization Algorithms

    Science.gov (United States)

    Marcoulides, George A.; Drezner, Zvi

    2003-01-01

    Ant colony optimization is a recently proposed heuristic procedure inspired by the behavior of real ants. This article applies the procedure to model specification searches in structural equation modeling and reports the results. The results demonstrate the capabilities of ant colony optimization algorithms for conducting automated searches.

  3. The non-local bootstrap--estimation of uncertainty in diffusion MRI.

    Science.gov (United States)

    Yap, Pew-Thian; An, Hongyu; Chen, Yasheng; Shen, Dinggang

    2013-01-01

    Diffusion MRI is a noninvasive imaging modality that allows for the estimation and visualization of white matter connectivity patterns in the human brain. However, due to the low signal-to-noise ratio (SNR) nature of diffusion data, deriving useful statistics from the data is adversely affected by different sources of measurement noise. This is aggravated by the fact that the sampling distribution of the statistic of interest is often complex and unknown. In situations as such, the bootstrap, due to its distribution-independent nature, is an appealing tool for the estimation of the variability of almost any statistic, without relying on complicated theoretical calculations, but purely on computer simulation. In this work, we present new bootstrap strategies for variability estimation of diffusion statistics in association with noise. In contrast to the residual bootstrap, which relies on a predetermined data model, or the repetition bootstrap, which requires repeated signal measurements, our approach, called the non-local bootstrap (NLB), is non-parametric and obviates the need for time-consuming multiple acquisitions. The key assumption of NLB is that local image structures recur in the image. We exploit this self-similarity via a multivariate non-parametric kernel regression framework for bootstrap estimation of uncertainty. Evaluation of NLB using a set of high-resolution diffusion-weighted images, with lower than usual SNR due to the small voxel size, indicates that NLB is markedly more robust to noise and results in more accurate inferences. PMID:24683985

  4. SHERLOCK: A quasi-model-independent new physics search strategy.

    Science.gov (United States)

    Knuteson, Bruce

    2000-04-01

    We develop a quasi-model-independent prescription for searching for physics responsible for the electroweak symmetry breaking in the Standard Model, and show a preliminary version of what we find when this prescription is applied to the DZero data.

  5. Early Stop Criterion from the Bootstrap Ensemble

    DEFF Research Database (Denmark)

    Hansen, Lars Kai; Larsen, Jan; Fog, Torben L.

    1997-01-01

    This paper addresses the problem of generalization error estimation in neural networks. A new early stop criterion based on a Bootstrap estimate of the generalization error is suggested. The estimate does not require the network to be trained to the minimum of the cost function, as required...... by other methods based on asymptotic theory. Moreover, in contrast to methods based on cross-validation which require data left out for testing, and thus biasing the estimate, the Bootstrap technique does not have this disadvantage. The potential of the suggested technique is demonstrated on various time...

  6. Bootstrap percolation: a renormalisation group approach

    International Nuclear Information System (INIS)

    In bootstrap percolation, sites are occupied at random with probability p, but each site is considered active only if at least m of its neighbours are also active. Within an approximate position-space renormalization group framework on a square lattice we obtain the behaviour of the critical concentration p (sub)c and of the critical exponents ν and β for m = 0 (ordinary percolation), 1,2 and 3. We find that the bootstrap percolation problem can be cast into different universality classes, characterized by the values of m. (author)

  7. Conference on Bootstrapping and Related Techniques

    CERN Document Server

    Rothe, Günter; Sendler, Wolfgang

    1992-01-01

    This book contains 30 selected, refereed papers from an in- ternational conference on bootstrapping and related techni- ques held in Trier 1990. Thepurpose of the book is to in- form about recent research in the area of bootstrap, jack- knife and Monte Carlo Tests. Addressing the novice and the expert it covers as well theoretical as practical aspects of these statistical techniques. Potential users in different disciplines as biometry, epidemiology, computer science, economics and sociology but also theoretical researchers s- hould consult the book to be informed on the state of the art in this area.

  8. Ringed Seal Search for Global Optimization via a Sensitive Search Model.

    Directory of Open Access Journals (Sweden)

    Younes Saadi

    Full Text Available The efficiency of a metaheuristic algorithm for global optimization is based on its ability to search and find the global optimum. However, a good search often requires to be balanced between exploration and exploitation of the search space. In this paper, a new metaheuristic algorithm called Ringed Seal Search (RSS is introduced. It is inspired by the natural behavior of the seal pup. This algorithm mimics the seal pup movement behavior and its ability to search and choose the best lair to escape predators. The scenario starts once the seal mother gives birth to a new pup in a birthing lair that is constructed for this purpose. The seal pup strategy consists of searching and selecting the best lair by performing a random walk to find a new lair. Affected by the sensitive nature of seals against external noise emitted by predators, the random walk of the seal pup takes two different search states, normal state and urgent state. In the normal state, the pup performs an intensive search between closely adjacent lairs; this movement is modeled via a Brownian walk. In an urgent state, the pup leaves the proximity area and performs an extensive search to find a new lair from sparse targets; this movement is modeled via a Levy walk. The switch between these two states is realized by the random noise emitted by predators. The algorithm keeps switching between normal and urgent states until the global optimum is reached. Tests and validations were performed using fifteen benchmark test functions to compare the performance of RSS with other baseline algorithms. The results show that RSS is more efficient than Genetic Algorithm, Particles Swarm Optimization and Cuckoo Search in terms of convergence rate to the global optimum. The RSS shows an improvement in terms of balance between exploration (extensive and exploitation (intensive of the search space. The RSS can efficiently mimic seal pups behavior to find best lair and provide a new algorithm to be

  9. Ringed Seal Search for Global Optimization via a Sensitive Search Model.

    Science.gov (United States)

    Saadi, Younes; Yanto, Iwan Tri Riyadi; Herawan, Tutut; Balakrishnan, Vimala; Chiroma, Haruna; Risnumawan, Anhar

    2016-01-01

    The efficiency of a metaheuristic algorithm for global optimization is based on its ability to search and find the global optimum. However, a good search often requires to be balanced between exploration and exploitation of the search space. In this paper, a new metaheuristic algorithm called Ringed Seal Search (RSS) is introduced. It is inspired by the natural behavior of the seal pup. This algorithm mimics the seal pup movement behavior and its ability to search and choose the best lair to escape predators. The scenario starts once the seal mother gives birth to a new pup in a birthing lair that is constructed for this purpose. The seal pup strategy consists of searching and selecting the best lair by performing a random walk to find a new lair. Affected by the sensitive nature of seals against external noise emitted by predators, the random walk of the seal pup takes two different search states, normal state and urgent state. In the normal state, the pup performs an intensive search between closely adjacent lairs; this movement is modeled via a Brownian walk. In an urgent state, the pup leaves the proximity area and performs an extensive search to find a new lair from sparse targets; this movement is modeled via a Levy walk. The switch between these two states is realized by the random noise emitted by predators. The algorithm keeps switching between normal and urgent states until the global optimum is reached. Tests and validations were performed using fifteen benchmark test functions to compare the performance of RSS with other baseline algorithms. The results show that RSS is more efficient than Genetic Algorithm, Particles Swarm Optimization and Cuckoo Search in terms of convergence rate to the global optimum. The RSS shows an improvement in terms of balance between exploration (extensive) and exploitation (intensive) of the search space. The RSS can efficiently mimic seal pups behavior to find best lair and provide a new algorithm to be used in global

  10. A Large Sample Study of the Bayesian Bootstrap

    OpenAIRE

    Lo, Albert Y.

    1987-01-01

    An asymptotic justification of the Bayesian bootstrap is given. Large-sample Bayesian bootstrap probability intervals for the mean, the variance and bands for the distribution, the smoothed density and smoothed rate function are also provided.

  11. The use of the bootstrap in the analysis of case-control studies with missing data

    DEFF Research Database (Denmark)

    Siersma, Volkert Dirk; Johansen, Christoffer

    2004-01-01

    nonparametric bootstrap, bootstrap confidence intervals, missing values, multiple imputation, matched case-control study......nonparametric bootstrap, bootstrap confidence intervals, missing values, multiple imputation, matched case-control study...

  12. How to Bootstrap a Human Communication System

    Science.gov (United States)

    Fay, Nicolas; Arbib, Michael; Garrod, Simon

    2013-01-01

    How might a human communication system be bootstrapped in the absence of conventional language? We argue that motivated signs play an important role (i.e., signs that are linked to meaning by structural resemblance or by natural association). An experimental study is then reported in which participants try to communicate a range of pre-specified…

  13. Pulling Econometrics Students up by Their Bootstraps

    Science.gov (United States)

    O'Hara, Michael E.

    2014-01-01

    Although the concept of the sampling distribution is at the core of much of what we do in econometrics, it is a concept that is often difficult for students to grasp. The thought process behind bootstrapping provides a way for students to conceptualize the sampling distribution in a way that is intuitive and visual. However, teaching students to…

  14. A Bootstrap Procedure of Propensity Score Estimation

    Science.gov (United States)

    Bai, Haiyan

    2013-01-01

    Propensity score estimation plays a fundamental role in propensity score matching for reducing group selection bias in observational data. To increase the accuracy of propensity score estimation, the author developed a bootstrap propensity score. The commonly used propensity score matching methods: nearest neighbor matching, caliper matching, and…

  15. Bootstrapping Density-Weighted Average Derivatives

    DEFF Research Database (Denmark)

    Cattaneo, Matias D.; Crump, Richard K.; Jansson, Michael

    Employing the "small bandwidth" asymptotic framework of Cattaneo, Crump, and Jansson (2009), this paper studies the properties of a variety of bootstrap-based inference procedures associated with the kernel-based density-weighted averaged derivative estimator proposed by Powell, Stock, and Stoker...

  16. Discussion on the paper "Analyzing short time series data from periodically fluctuating rodent populations by threshold models: A nearest block bootstrap approach"

    Institute of Scientific and Technical Information of China (English)

    LI W.K.; LI GuoDong

    2009-01-01

    @@ The authors are to be congratulated for an innovative paper in terms of both modelling methodology and subject matter significance. The analysis of short time series is known to be difficult even for linear models.

  17. Weak Convergence of Smoothed and Nonsmoothed Bootstrap Quantile Estimates

    OpenAIRE

    Falk, M; Reiss, R.-D.

    1989-01-01

    Under fairly general assumptions on the underlying distribution function, the bootstrap process, pertaining to the sample $q$-quantile, converges weakly in $D_\\mathbb{R}$ to the standard Brownian motion. Furthermore, weak convergence of a smoothed bootstrap quantile estimate is proved which entails that in this particular case the smoothed bootstrap estimate outperforms the nonsmoothed one.

  18. Testing for asymmetry in economic time series using bootstrap methods

    OpenAIRE

    Claudio Lupi; Patrizia Ordine

    2001-01-01

    In this paper we show that phase-scrambling bootstrap offers a natural framework for asymmetry testing in economic time series. A comparison with other bootstrap schemes is also sketched. A Monte Carlo analysis is carried out to evaluate the size and power properties of the phase-scrambling bootstrap-based test.

  19. Search Strategies for Top Partners in Composite Higgs models

    CERN Document Server

    Gripaios, Ben; Parker, M A; Sutherland, Dave

    2014-01-01

    We consider how best to search for top partners in generic composite Higgs models. We begin by classifying the possible group representations carried by top partners in models with and without a custodial $SU(2)\\times SU(2) \\rtimes \\mathbb{Z}_2$ symmetry protecting the rate for $Z \\rightarrow b\\overline{b}$ decays. We identify a number of minimal models whose top partners only have electric charges of $\\frac{1}{3}, \\frac{2}{3},$ or $\\frac{4}{3}$ and thus decay to top or bottom quarks via a single Higgs or electroweak gauge boson. We develop an inclusive search for these based on a top veto, which we find to be more effective than existing searches. Less minimal models feature light states that can be sought in final states with like-sign leptons and so we find that 2 straightforward LHC searches give a reasonable coverage of the gamut of composite Higgs models.

  20. Combining search space partition and search Space partition and abstraction for LTL model checking

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The state space explosion problem is still the key obstacle for applying model checking to systems of industrial size.Abstraction-based methods have been particularly successful in this regard.This paper presents an approach based on refinement of search space partition and abstraction which combines these two techniques for reducing the complexity of model checking.The refinement depends on the representation of each portion of search space. Especially, search space can be refined stepwise to get a better reduction. As reported in the case study, the Integration of search space partition and abstraction improves the efficiencyof verification with respect to the requirement of memory and obtains significant advantage over the use of each of them in isolation.

  1. Iterated smoothed bootstrap confidence intervals for population quantiles

    OpenAIRE

    Lee, SMS; Ho, YHS

    2005-01-01

    This paper investigates the effects of smoothed bootstrap iterations on coverage probabilities of smoothed bootstrap and bootstrap-t confidence intervals for population quantiles, and establishes the optimal kernel bandwidths at various stages of the smoothing procedures. The conventional smoothed bootstrap and bootstrap-t methods have been known to yield one-sided coverage errors of orders O(n−1/2) and o(n−2/3), respectively, for intervals based on the sample quantile of a random sample of s...

  2. The Block-block Bootstrap: Improved Asymptotic Refinements

    OpenAIRE

    Donald W.K. Andrews

    2002-01-01

    The asymptotic refinements attributable to the block bootstrap for time series are not as large as those of the nonparametric iid bootstrap or the parametric bootstrap. One reason is that the independence between the blocks in the block bootstrap sample does not mimic the dependence structure of the original sample. This is the join-point problem. In this paper, we propose a method of solving this problem. The idea is not to alter the block bootstrap. Instead, we alter the original sample sta...

  3. The cluster bootstrap consistency in generalized estimating equations

    KAUST Repository

    Cheng, Guang

    2013-03-01

    The cluster bootstrap resamples clusters or subjects instead of individual observations in order to preserve the dependence within each cluster or subject. In this paper, we provide a theoretical justification of using the cluster bootstrap for the inferences of the generalized estimating equations (GEE) for clustered/longitudinal data. Under the general exchangeable bootstrap weights, we show that the cluster bootstrap yields a consistent approximation of the distribution of the regression estimate, and a consistent approximation of the confidence sets. We also show that a computationally more efficient one-step version of the cluster bootstrap provides asymptotically equivalent inference. © 2012.

  4. Mathematical Modeling of Competition in Sponsored Search Market

    OpenAIRE

    Liu, Jian; Chiu, Dah Ming

    2010-01-01

    Sponsored search mechanisms have drawn much attention from both academic community and industry in recent years since the seminal papers of [13] and [14]. However, most of the existing literature concentrates on the mechanism design and analysis within the scope of only one search engine in the market. In this paper we propose a mathematical framework for modeling the interaction of publishers, advertisers and end users in a competitive market. We first consider the monopoly market model and ...

  5. A comparison of four different block bootstrap methods

    Directory of Open Access Journals (Sweden)

    Boris Radovanov

    2014-12-01

    Full Text Available The paper contains a description of four different block bootstrap methods, i.e., non-overlapping block bootstrap, overlapping block bootstrap (moving block bootstrap, stationary block bootstrap and subsampling. Furthermore, the basic goal of this paper is to quantify relative efficiency of each mentioned block bootstrap procedure and then to compare those methods. To achieve the goal, we measure mean square errors of estimation variance returns. The returns are calculated from 1250 daily observations of Serbian stock market index values BELEX15 from April 2009 to April 2014. Thereby, considering the effects of potential changes in decisions according to variations in the sample length and purposes of the use, this paper introduces stability analysis which contains robustness testing of the different sample size and the different block length. Testing results indicate some changes in bootstrap method efficiencies when altering the sample size or the block length.

  6. ON THE COMPARISON OF BAYESIAN INFORMATION CRITERION AND DRAPER'S INFORMATION CRITERION IN SELECTION OF AN ASYMMETRIC PRICE RELATIONSHIP: BOOTSTRAP SIMULATION RESULTS

    Directory of Open Access Journals (Sweden)

    Henry de-Graft Acquah

    2013-03-01

    Full Text Available Alternative formulations of the Bayesian Information Criteria provide a basis for choosing between competing methods for detecting price asymmetry. However, very little is understood about their performance in the asymmetric price transmission modelling framework. In addressing this issue, this paper introduces and applies parametric bootstrap techniques to evaluate the ability of Bayesian Information Criteria (BIC and Draper's Information Criteria (DIC in discriminating between alternative asymmetric price transmission models under various error and sample size conditions. The results of the bootstrap simulations indicate that model selection performance depends on bootstrap sample size and the amount of noise in the data generating process. The Bayesian criterion clearly identifies the true asymmetric model out of different competing models in the presence of bootstrap samples. Draper's Information Criteria (DIC; Draper, 1995 outperforms BIC at either larger bootstrap sample size or lower noise level.

  7. Research on the User Interest Modeling of Personalized Search Engine

    Institute of Scientific and Technical Information of China (English)

    LI Zhengwei; XIA Shixiong; NIU Qiang; XIA Zhanguo

    2007-01-01

    At present, how to enable Search Engine to construct user personal interest model initially, master user's personalized information timely and provide personalized services accurately have become the hotspot in the research of Search Engine area.Aiming at the problems of user model's construction and combining techniques of manual customization modeling and automatic analytical modeling, a User Interest Model (UIM) is proposed in the paper. On the basis of it, the corresponding establishment and update algorithms of User Interest Profile (UIP) are presented subsequently. Simulation tests proved that the UIM proposed and corresponding algorithms could enhance the retrieval precision effectively and have superior adaptability.

  8. Consistency of the jackknife-after-bootstrap variance estimator for the bootstrap quantiles of a Studentized statistic

    OpenAIRE

    Lahiri, S. N.

    2005-01-01

    Efron [J. Roy. Statist. Soc. Ser. B 54 (1992) 83--111] proposed a computationally efficient method, called the jackknife-after-bootstrap, for estimating the variance of a bootstrap estimator for independent data. For dependent data, a version of the jackknife-after-bootstrap method has been recently proposed by Lahiri [Econometric Theory 18 (2002) 79--98]. In this paper it is shown that the jackknife-after-bootstrap estimators of the variance of a bootstrap quantile are consistent for both de...

  9. Extremal bootstrapping: go with the flow

    CERN Document Server

    El-Showk, Sheer

    2016-01-01

    The extremal functional method determines approximate solutions to the constraints of crossing symmetry, which saturate bounds on the space of unitary CFTs. We show that such solutions are characterized by extremality conditions, which may be used to flow continuously along the boundaries of parameter space. Along the flow there is generically no further need for optimization, which dramatically reduces computational requirements, bringing calculations from the realm of computing clusters to laptops. Conceptually, extremality sheds light on possible ways to bootstrap without positivity, extending the method to non-unitary theories, and implies that theories saturating bounds, and especially those sitting at kinks, have unusually sparse spectra. We discuss several applications, including the first high-precision bootstrap of a non-unitary CFT.

  10. The $(2,0)$ superconformal bootstrap

    CERN Document Server

    Beem, Christopher; Rastelli, Leonardo; van Rees, Balt C

    2016-01-01

    We develop the conformal bootstrap program for six-dimensional conformal field theories with $(2,0)$ supersymmetry, focusing on the universal four-point function of stress tensor multiplets. We review the solution of the superconformal Ward identities and describe the superconformal block decomposition of this correlator. We apply numerical bootstrap techniques to derive bounds on OPE coefficients and scaling dimensions from the constraints of crossing symmetry and unitarity. We also derive analytic results for the large spin spectrum using the lightcone expansion of the crossing equation. Our principal result is strong evidence that the $A_1$ theory realizes the minimal allowed central charge $(c=25)$ for any interacting $(2,0)$ theory. This implies that the full stress tensor four-point function of the $A_1$ theory is the unique unitary solution to the crossing symmetry equation at $c=25$. For this theory, we estimate the scaling dimensions of the lightest unprotected operators appearing in the stress tenso...

  11. Simplified models for dark matter searches at the LHC

    NARCIS (Netherlands)

    J. Abdallah; . et al; P. de Jong; S. Liem; C. McCabe; P. Pani; D. Salek; C. Tunnell

    2015-01-01

    This document outlines a set of simplified models for dark matter and its interactions with Standard Model particles. It is intended to summarize the main characteristics that these simplified models have when applied to dark matter searches at the LHC, and to provide a number of useful expressions

  12. Insight from uncertainty: bootstrap-derived diffusion metrics differentially predict memory function among older adults.

    Science.gov (United States)

    Vorburger, Robert S; Habeck, Christian G; Narkhede, Atul; Guzman, Vanessa A; Manly, Jennifer J; Brickman, Adam M

    2016-01-01

    Diffusion tensor imaging suffers from an intrinsic low signal-to-noise ratio. Bootstrap algorithms have been introduced to provide a non-parametric method to estimate the uncertainty of the measured diffusion parameters. To quantify the variability of the principal diffusion direction, bootstrap-derived metrics such as the cone of uncertainty have been proposed. However, bootstrap-derived metrics are not independent of the underlying diffusion profile. A higher mean diffusivity causes a smaller signal-to-noise ratio and, thus, increases the measurement uncertainty. Moreover, the goodness of the tensor model, which relies strongly on the complexity of the underlying diffusion profile, influences bootstrap-derived metrics as well. The presented simulations clearly depict the cone of uncertainty as a function of the underlying diffusion profile. Since the relationship of the cone of uncertainty and common diffusion parameters, such as the mean diffusivity and the fractional anisotropy, is not linear, the cone of uncertainty has a different sensitivity. In vivo analysis of the fornix reveals the cone of uncertainty to be a predictor of memory function among older adults. No significant correlation occurs with the common diffusion parameters. The present work not only demonstrates the cone of uncertainty as a function of the actual diffusion profile, but also discloses the cone of uncertainty as a sensitive predictor of memory function. Future studies should incorporate bootstrap-derived metrics to provide more comprehensive analysis.

  13. Loop calculus and bootstrap-belief propagation for perfect matchings on arbitrary graphs

    Science.gov (United States)

    Chertkov, M.; Gelfand, A.; Shin, J.

    2013-12-01

    This manuscript discusses computation of the Partition Function (PF) and the Minimum Weight Perfect Matching (MWPM) on arbitrary, non-bipartite graphs. We present two novel problem formulations - one for computing the PF of a Perfect Matching (PM) and one for finding MWPMs - that build upon the inter-related Bethe Free Energy (BFE), Belief Propagation (BP), Loop Calculus (LC), Integer Linear Programming and Linear Programming frameworks. First, we describe an extension of the LC framework to the PM problem. The resulting formulas, coined (fractional) Bootstrap-BP, express the PF of the original model via the BFE of an alternative PM problem. We then study the zero-temperature version of this Bootstrap-BP formula for approximately solving the MWPM problem. We do so by leveraging the Bootstrap-BP formula to construct a sequence of MWPM problems, where each new problem in the sequence is formed by contracting odd-sized cycles (or blossoms) from the previous problem. This Bootstrap-and-Contract procedure converges reliably and generates an empirically tight upper bound for the MWPM. We conclude by discussing the relationship between our iterative procedure and the famous Blossom Algorithm of Edmonds '65 and demonstrate the performance of the Bootstrap-and-Contract approach on a variety of weighted PM problems.

  14. Loop calculus and bootstrap-belief propagation for perfect matchings on arbitrary graphs

    International Nuclear Information System (INIS)

    This manuscript discusses computation of the Partition Function (PF) and the Minimum Weight Perfect Matching (MWPM) on arbitrary, non-bipartite graphs. We present two novel problem formulations – one for computing the PF of a Perfect Matching (PM) and one for finding MWPMs – that build upon the inter-related Bethe Free Energy (BFE), Belief Propagation (BP), Loop Calculus (LC), Integer Linear Programming and Linear Programming frameworks. First, we describe an extension of the LC framework to the PM problem. The resulting formulas, coined (fractional) Bootstrap-BP, express the PF of the original model via the BFE of an alternative PM problem. We then study the zero-temperature version of this Bootstrap-BP formula for approximately solving the MWPM problem. We do so by leveraging the Bootstrap-BP formula to construct a sequence of MWPM problems, where each new problem in the sequence is formed by contracting odd-sized cycles (or blossoms) from the previous problem. This Bootstrap-and-Contract procedure converges reliably and generates an empirically tight upper bound for the MWPM. We conclude by discussing the relationship between our iterative procedure and the famous Blossom Algorithm of Edmonds '65 and demonstrate the performance of the Bootstrap-and-Contract approach on a variety of weighted PM problems

  15. Parameters estimation of sinter ore match poor information combined bootstrap method, grey analysis and artificial neural networks models%烧结配矿乏信息灰自助神经网络特征参数估计

    Institute of Scientific and Technical Information of China (English)

    刘代飞; 李军; 袁礼顺

    2012-01-01

    采用BP神经网络建立铁矿烧结评价函数分析烧结配矿特征信息.由中和矿的化学成分、黏附粒子及成核粒子共13个参数构成BP模型输入,烧结矿转鼓强度和烧结速度为模型输出.由100组训练和50组测试数据通过建模确定BP模型隐层节点为27.采用Bootstrap方法处理正交试验数据,采用灰分析提取数据动态信息.提出一种基于人工神经网络模型的参数估计概率求解策略,其中系统整体和动态信息由神经网络模型综合,参数特征值由蒙特卡罗模拟结合概率计算获得.估计和模拟结果为烧结配矿乏信息分析提供一种有效途径.%An iron ore sinter evaluating function based on back propagation neural networks (BP) model was adopted to express and analyze complex sinter parameters information. The basic BP model consists of 13 input nodes, 27 hidden nodes and 2 output nodes. The input parameters included essential chemical composition parameters, quantity of conglutination particle and nucleolus particle of mixed ores; the output parameters consisted of sintering velocity and tumbler strength; and the hidden node was obtained through BP modeling with 100 groups of data for training and 50 groups of data for testing. Static information of experiments data was processed by Bootstrap method and change tendency information of process data was analyzed by grey analysis method. A kind of parameter estimation scheme was proposed based on BP model and statistics probability calculation. Sinter general and dynamic information was synthesized by the neural networks models, and estimation values of parameters within the ore evaluating functions were deduced by Monte Carlo simulation integrated statistics probability calculation. The estimation and simulation results provide an effective analysis means for sinter poor information.

  16. Cognitive control in majority search: A computational modeling approach

    Directory of Open Access Journals (Sweden)

    Hongbin eWang

    2011-02-01

    Full Text Available Despite the importance of cognitive control in many cognitive tasks involving uncertainty, the computational mechanisms of cognitive control in response to uncertainty remain unclear. In this study, we develop biologically realistic neural network models to investigate the instantiation of cognitive control in a majority function task, where one determines the category to which the majority of items in a group belong. Two models are constructed, both of which include the same set of modules representing task-relevant brain functions and share the same model structure. However, with a critical change of a model parameter setting, the two models implement two different underlying algorithms: one for grouping search (where a subgroup of items are sampled and re-sampled until a congruent sample is found and the other for self-terminating search (where the items are scanned and counted one-by-one until the majority is decided. The two algorithms hold distinct implications for the involvement of cognitive control. The modeling results show that while both models are able to perform the task, the grouping search model fit the human data better than the self-terminating search model. An examination of the dynamics underlying model performance reveals how cognitive control might be instantiated in the brain via the V4-ACC-LPFC-IPS loop for computing the majority function.

  17. Interaction of bootstrap-current-driven magnetic islands

    International Nuclear Information System (INIS)

    The formation and interaction of fluctuating neoclassical pressure gradient driven magnetic islands is examined. The interaction of magnetic islands produces a stochastic region around the separatrices of the islands. This interaction causes the island pressure profile to be broadened, reducing the island bootstrap current and drive for the magnetic island. A model is presented that describes the magnetic topology as a bath of interacting magnetic islands with low to medium poloidal mode number (m congruent 3-30). The islands grow by the bootstrap current effect and damp due to the flattening of the pressure profile near the island separatrix caused by the interaction of the magnetic islands. The effect of this sporadic growth and decay of the islands (''magnetic bubbling'') is not normally addressed in theories of plasma transport due to magnetic fluctuations. The nature of the transport differs from statistical approaches to magnetic turbulence since the radial step size of the plasma transport is now given by the characteristic island width. This model suggests that tokamak experiments have relatively short-lived, coherent, long wavelength magnetic oscillations present in the steep pressure-gradient regions of the plasma. 42 refs

  18. Stochastic Models for Budget Optimization in Search-Based Advertising

    OpenAIRE

    Muthukrishnan, S.; Pal, Martin; Svitkina, Zoya

    2006-01-01

    Internet search companies sell advertisement slots based on users' search queries via an auction. Advertisers have to determine how to place bids on the keywords of their interest in order to maximize their return for a given budget: this is the budget optimization problem. The solution depends on the distribution of future queries. In this paper, we formulate stochastic versions of the budget optimization problem based on natural probabilistic models of distribution over future queries, and ...

  19. Modeling Knowledge Resource Selection in Expert Librarian Search

    OpenAIRE

    David R. Kaufman; MEHRYAR, Maryam; Chase, Herbert; Hung, Peter; CHILOV, Marina; Johnson, Stephen B.; Mendonca, Eneida

    2009-01-01

    Providing knowledge at the point of care offers the possibility for reducing error and improving patient outcomes. However, the vast majority of physician’s information needs are not met in a timely fashion. The research presented in this paper models an expert librarian’s search strategies as it pertains to the selection and use of various electronic information resources. The 10 searches conducted by the librarian to address physician’s information needs, varied in terms of complexity and q...

  20. How Users Search the Mobile Web: A Model for Understanding the Impact of Motivation and Context on Search Behaviors

    Directory of Open Access Journals (Sweden)

    Dan Wu

    2016-03-01

    Full Text Available Purpose: This study explores how search motivation and context influence mobile Web search behaviors. Design/methodology/approach: We studied 30 experienced mobile Web users via questionnaires, semi-structured interviews, and an online diary tool that participants used to record their daily search activities. SQLite Developer was used to extract data from the users' phone logs for correlation analysis in Statistical Product and Service Solutions (SPSS. Findings: One quarter of mobile search sessions were driven by two or more search motivations. It was especially difficult to distinguish curiosity from time killing in particular user reporting. Multi-dimensional contexts and motivations influenced mobile search behaviors, and among the context dimensions, gender, place, activities they engaged in while searching, task importance, portal, and interpersonal relations (whether accompanied or alone when searching correlated with each other. Research limitations: The sample was comprised entirely of college students, so our findings may not generalize to other populations. More participants and longer experimental duration will improve the accuracy and objectivity of the research. Practical implications: Motivation analysis and search context recognition can help mobile service providers design applications and services for particular mobile contexts and usages. Originality/value: Most current research focuses on specific contexts, such as studies on place, or other contextual influences on mobile search, and lacks a systematic analysis of mobile search context. Based on analysis of the impact of mobile search motivations and search context on search behaviors, we built a multi-dimensional model of mobile search behaviors.

  1. A Search Model with a Quasi-Network

    DEFF Research Database (Denmark)

    Ejarque, Joao Miguel

    This paper adds a quasi-network to a search model of the labor market. Fitting the model to an average unemployment rate and to other moments in the data implies the presence of the network is not noticeable in the basic properties of the unemployment and job finding rates. However, the network c...

  2. Fitting Equilibrium Search Models to Labour Market Data

    DEFF Research Database (Denmark)

    Bowlus, Audra J.; Kiefer, Nicholas M.; Neumann, George R.

    1996-01-01

    Specification and estimation of a Burdett-Mortensen type equilibrium search model is considered. The estimation is nonstandard. An estimation strategy asymptotically equivalent to maximum likelihood is proposed and applied. The results indicate that specifications with a small number of productiv...... of productivity types fit the data well compared to the homogeneous model....

  3. Tax Policy in a Model of Search with Training

    NARCIS (Netherlands)

    Boone, J.; de Mooij, R.A.

    2000-01-01

    This paper develops a model of search on the labour market with training. The model reveals how the tax system can restore the social optimum if the Hosios condition is not satisfied in the private equilibrium. Furthermore, the effects are explored of a second-best reform from average to marginal ta

  4. Bootstrap embedding: An internally consistent fragment-based method

    Science.gov (United States)

    Welborn, Matthew; Tsuchimochi, Takashi; Van Voorhis, Troy

    2016-08-01

    Strong correlation poses a difficult problem for electronic structure theory, with computational cost scaling quickly with system size. Fragment embedding is an attractive approach to this problem. By dividing a large complicated system into smaller manageable fragments "embedded" in an approximate description of the rest of the system, we can hope to ameliorate the steep cost of correlated calculations. While appealing, these methods often converge slowly with fragment size because of small errors at the boundary between fragment and bath. We describe a new electronic embedding method, dubbed "Bootstrap Embedding," a self-consistent wavefunction-in-wavefunction embedding theory that uses overlapping fragments to improve the description of fragment edges. We apply this method to the one dimensional Hubbard model and a translationally asymmetric variant, and find that it performs very well for energies and populations. We find Bootstrap Embedding converges rapidly with embedded fragment size, overcoming the surface-area-to-volume-ratio error typical of many embedding methods. We anticipate that this method may lead to a low-scaling, high accuracy treatment of electron correlation in large molecular systems.

  5. Bootstrap embedding: An internally consistent fragment-based method.

    Science.gov (United States)

    Welborn, Matthew; Tsuchimochi, Takashi; Van Voorhis, Troy

    2016-08-21

    Strong correlation poses a difficult problem for electronic structure theory, with computational cost scaling quickly with system size. Fragment embedding is an attractive approach to this problem. By dividing a large complicated system into smaller manageable fragments "embedded" in an approximate description of the rest of the system, we can hope to ameliorate the steep cost of correlated calculations. While appealing, these methods often converge slowly with fragment size because of small errors at the boundary between fragment and bath. We describe a new electronic embedding method, dubbed "Bootstrap Embedding," a self-consistent wavefunction-in-wavefunction embedding theory that uses overlapping fragments to improve the description of fragment edges. We apply this method to the one dimensional Hubbard model and a translationally asymmetric variant, and find that it performs very well for energies and populations. We find Bootstrap Embedding converges rapidly with embedded fragment size, overcoming the surface-area-to-volume-ratio error typical of many embedding methods. We anticipate that this method may lead to a low-scaling, high accuracy treatment of electron correlation in large molecular systems. PMID:27544082

  6. Passage relevance models for genomics search

    Directory of Open Access Journals (Sweden)

    Frieder Ophir

    2009-03-01

    Full Text Available Abstract We present a passage relevance model for integrating syntactic and semantic evidence of biomedical concepts and topics using a probabilistic graphical model. Component models of topics, concepts, terms, and document are represented as potential functions within a Markov Random Field. The probability of a passage being relevant to a biologist's information need is represented as the joint distribution across all potential functions. Relevance model feedback of top ranked passages is used to improve distributional estimates of query concepts and topics in context, and a dimensional indexing strategy is used for efficient aggregation of concept and term statistics. By integrating multiple sources of evidence including dependencies between topics, concepts, and terms, we seek to improve genomics literature passage retrieval precision. Using this model, we are able to demonstrate statistically significant improvements in retrieval precision using a large genomics literature corpus.

  7. Charmed baryons in bootstrap quark model

    OpenAIRE

    Gerasyuta, S. M.; Ivanov, D.V.

    2001-01-01

    In the framework of dispersion relation technique the relativistic three-quark equations including heavy quarks are found. The approximate solutions of the relativistic three-particles equations based on the extraction of leading singularities of amplitudes are obtained. The mass values of S-wave multiplets of charmed baryons are calculated.

  8. Change-point in stochastic design regression and the bootstrap

    OpenAIRE

    Seijo, Emilio; Sen, Bodhisattva

    2011-01-01

    In this paper we study the consistency of different bootstrap procedures for constructing confidence intervals (CIs) for the unique jump discontinuity (change-point) in an otherwise smooth regression function in a stochastic design setting. This problem exhibits nonstandard asymptotics and we argue that the standard bootstrap procedures in regression fail to provide valid confidence intervals for the change-point. We propose a version of smoothed bootstrap, illustrate its remarkable finite sa...

  9. Is Bootstrap Really Helpful in Point Process Statistics?

    OpenAIRE

    Snethlage, Martin

    2000-01-01

    There are some papers which describe the use of bootstrap techniques in point process statistics. The aim of the present paper is to show that the form in which bootstrap is used there is dubious. In case of variance estimation of pair correlation function estimators the used bootstrap techniques lead to results which can be obtained simpler without simulation; furthermore, they differ from the desired results. The problem to obtain confidence regions for the intensity function of inhomogeneo...

  10. Stationary bootstrapping realized volatility under market microstructure noise

    OpenAIRE

    Hwang, Eunju; Shin, Dong Wan

    2013-01-01

    Large-sample validity is proved for stationary bootstrapping of a bias-corrected realized volatility under market microstructure noise, which enables us to construct a bootstrap confidence interval of integrated volatility. A finite-sample simulation shows that the stationary bootstrapping confidence interval outperforms existing ones which are constructed ignoring market microstructure noise or using asymptotic normality for the bias-corrected realized volatility.

  11. Bootstrap position analysis for forecasting low flow frequency

    Science.gov (United States)

    Tasker, Gary D.; Dunne, P.

    1997-01-01

    A method of random resampling of residuals from stochastic models is used to generate a large number of 12-month-long traces of natural monthly runoff to be used in a position analysis model for a water-supply storage and delivery system. Position analysis uses the traces to forecast the likelihood of specified outcomes such as reservoir levels falling below a specified level or streamflows falling below statutory passing flows conditioned on the current reservoir levels and streamflows. The advantages of this resampling scheme, called bootstrap position analysis, are that it does not rely on the unverifiable assumption of normality, fewer parameters need to be estimated directly from the data, and accounting for parameter uncertainty is easily done. For a given set of operating rules and water-use requirements for a system, water managers can use such a model as a decision-making tool to evaluate different operating rules. ?? ASCE,.

  12. Learning Curves and Bootstrap Estimates for Inference with Gaussian Processes: A Statistical Mechanics Study

    DEFF Research Database (Denmark)

    Malzahn, Dorthe; Opper, Manfred

    2003-01-01

    We employ the replica method of statistical physics to study the average case performance of learning systems. The new feature of our theory is that general distributions of data can be treated, which enables applications to real data. For a class of Bayesian prediction models which are based on ...... Gaussian processes, we discuss Bootstrap estimates for learning curves....

  13. A Class of Population Covariance Matrices in the Bootstrap Approach to Covariance Structure Analysis

    Science.gov (United States)

    Yuan, Ke-Hai; Hayashi, Kentaro; Yanagihara, Hirokazu

    2007-01-01

    Model evaluation in covariance structure analysis is critical before the results can be trusted. Due to finite sample sizes and unknown distributions of real data, existing conclusions regarding a particular statistic may not be applicable in practice. The bootstrap procedure automatically takes care of the unknown distribution and, for a given…

  14. Bootstrap confidence intervals for the process capability index under half-logistic distribution

    OpenAIRE

    Wararit Panichkitkosolkul

    2012-01-01

    This study concerns the construction of bootstrap confidence intervals for theprocess capability index in the case of half-logistic distribution. The bootstrap confidence intervals applied consist of standard bootstrap confidence interval, percentile bootstrap confidence interval and bias-corrected percentile bootstrap confidence interval. Using Monte Carlo simulations, the estimated coverage probabilities and average widths ofbootstrap confidence intervals are compared, with results showing ...

  15. A bootstrap approach to bump hunting

    Science.gov (United States)

    Silverman, B. W.

    1982-01-01

    An important question in cluster analysis and pattern recognition is the determination of the number of clusters into which a given population should be divided. Frequently, particularly when certain specific clustering methods are being used, the number of clusters is taken to be equal to the number of modes, or local maxima, in the probability density function underlying the given data set. The use of kernal density estimates in mode estimation is discussed. The test statistic to be used is defined and a bootstrap technique for assessing significance is given. An illustrative application is followed by an examination of the asymptotic behavior of the test statistic.

  16. Evaluating Neural Network Predictors by Bootstrapping

    OpenAIRE

    Blake LeBaron; Andreas S. Weigend

    1994-01-01

    We present a new method, inspired by the bootstrap, whose goal it is to determine the quality and reliability of a neural network predictor. Our method leads to more robust forecasting along with a large amount of statistical information on forecast performance that we exploit. We exhibit the method in the context of multi-variate time series prediction on financial data from the New York Stock Exchange. It turns out that the variation due to different resamplings (i.e., splits between traini...

  17. Development and test of an integrative model of job search behaviour

    OpenAIRE

    Van Hoye, Greet; Saks, Alan M.; Lievens, Filip; Weijters, Bert

    2015-01-01

    Research on job search and the theory of planned behavior (TPB) has identified job search attitude, subjective norm, and job search self-efficacy as the most proximal determinants of job seekers’ search intentions and subsequently job search behaviors. However, we do not yet know how more distal individual differences (e.g., personality) and situational factors (e.g., social context) might help to predict these key TPB determinants of job search behavior. In an integrative model of job search...

  18. Confidence Intervals for the Mean: To Bootstrap or Not to Bootstrap

    Science.gov (United States)

    Calzada, Maria E.; Gardner, Holly

    2011-01-01

    The results of a simulation conducted by a research team involving undergraduate and high school students indicate that when data is symmetric the student's "t" confidence interval for a mean is superior to the studied non-parametric bootstrap confidence intervals. When data is skewed and for sample sizes n greater than or equal to 10, the results…

  19. Language Models for Searching in Web Corpora

    NARCIS (Netherlands)

    J. Kamps; G.A. Mishne; M. de Rijke

    2005-01-01

    We describe our participation in the TREC 2004 Web and Terabyte tracks. For the web track, we employ mixture language models based on document full-text, incoming anchortext, and documents titles, with a range of webcentric priors. We provide a detailed analysis of the effect on relevance of documen

  20. Protein Folding: Search for Basic Physical Models

    Directory of Open Access Journals (Sweden)

    Ivan Y. Torshin

    2003-01-01

    Full Text Available How a unique three-dimensional structure is rapidly formed from the linear sequence of a polypeptide is one of the important questions in contemporary science. Apart from biological context of in vivo protein folding (which has been studied only for a few proteins, the roles of the fundamental physical forces in the in vitro folding remain largely unstudied. Despite a degree of success in using descriptions based on statistical and/or thermodynamic approaches, few of the current models explicitly include more basic physical forces (such as electrostatics and Van Der Waals forces. Moreover, the present-day models rarely take into account that the protein folding is, essentially, a rapid process that produces a highly specific architecture. This review considers several physical models that may provide more direct links between sequence and tertiary structure in terms of the physical forces. In particular, elaboration of such simple models is likely to produce extremely effective computational techniques with value for modern genomics.

  1. Content-Based Search on a Database of Geometric Models: Identifying Objects of Similar Shape

    Energy Technology Data Exchange (ETDEWEB)

    XAVIER, PATRICK G.; HENRY, TYSON R.; LAFARGE, ROBERT A.; MEIRANS, LILITA; RAY, LAWRENCE P.

    2001-11-01

    The Geometric Search Engine is a software system for storing and searching a database of geometric models. The database maybe searched for modeled objects similar in shape to a target model supplied by the user. The database models are generally from CAD models while the target model may be either a CAD model or a model generated from range data collected from a physical object. This document describes key generation, database layout, and search of the database.

  2. Performance of Bootstrap MCEWMA: Study case of Sukuk Musyarakah data

    Science.gov (United States)

    Safiih, L. Muhamad; Hila, Z. Nurul

    2014-07-01

    Sukuk Musyarakah is one of several instruments of Islamic bond investment in Malaysia, where the form of this sukuk is actually based on restructuring the conventional bond to become a Syariah compliant bond. The Syariah compliant is based on prohibition of any influence of usury, benefit or fixed return. Despite of prohibition, daily returns of sukuk are non-fixed return and in statistic, the data of sukuk returns are said to be a time series data which is dependent and autocorrelation distributed. This kind of data is a crucial problem whether in statistical and financing field. Returns of sukuk can be statistically viewed by its volatility, whether it has high volatility that describing the dramatically change of price and categorized it as risky bond or else. However, this crucial problem doesn't get serious attention among researcher compared to conventional bond. In this study, MCEWMA chart in Statistical Process Control (SPC) is mainly used to monitor autocorrelated data and its application on daily returns of securities investment data has gained widespread attention among statistician. However, this chart has always been influence by inaccurate estimation, whether on base model or its limit, due to produce large error and high of probability of signalling out-of-control process for false alarm study. To overcome this problem, a bootstrap approach used in this study, by hybridise it on MCEWMA base model to construct a new chart, i.e. Bootstrap MCEWMA (BMCEWMA) chart. The hybrid model, BMCEWMA, will be applied to daily returns of sukuk Musyarakah for Rantau Abang Capital Bhd. The performance of BMCEWMA base model showed that its more effective compare to real model, MCEWMA based on smaller error estimation, shorter the confidence interval and smaller false alarm. In other word, hybrid chart reduce the variability which shown by smaller error and false alarm. It concludes that the application of BMCEWMA is better than MCEWMA.

  3. Search of novel model for integrative medicine.

    Science.gov (United States)

    Patwardhan, Bhushan; Mutalik, Gururaj

    2014-03-01

    This article provides global and Indian scenario with strengths and limitations of present health care system. Affordability, accessibility and availability of health care coupled with disproportionate growth and double burden of diseases have become major concerns in India. This article emphasizes need for mindset change from illness-disease-drug centric curative to person-health-wellness centric preventive and promotive approaches. It highlights innovation deficit faced pharmaceutical industry and drugs being withdrawn from market for safety reasons. Medical pluralism is a growing trend and people are exploring various options including modern, traditional, complementary and alternative medicine. In such a situation, knowledge from Ayurveda, yoga, Chinese medicine and acupuncture may play an important role. We can evolve a suitable model by integrating modern and traditional systems of medicine for affordable health care. In the larger interest of global community, Indian and Chinese systems should share knowledge and experiences for mutual intellectual enrichments and work together to evolve a novel model of integrative medicine.

  4. Search for the fourth standard model family

    International Nuclear Information System (INIS)

    Existence of the fourth family follows from the basics of the standard model (SM) and the actual mass spectrum of the third family fermions. We discuss possible manifestations of the fourth SM family at existing and future colliders. The LHC and Tevatron potentials to discover the fourth SM family have been compared. The scenario with dominance of the anomalous decay modes of the fourth-family quarks has been considered in detail.

  5. Bootstrapping Security Policies for Wearable Apps Using Attributed Structural Graphs.

    Science.gov (United States)

    González-Tablas, Ana I; Tapiador, Juan E

    2016-05-11

    We address the problem of bootstrapping security and privacy policies for newly-deployed apps in wireless body area networks (WBAN) composed of smartphones, sensors and other wearable devices. We introduce a framework to model such a WBAN as an undirected graph whose vertices correspond to devices, apps and app resources, while edges model structural relationships among them. This graph is then augmented with attributes capturing the features of each entity together with user-defined tags. We then adapt available graph-based similarity metrics to find the closest app to a new one to be deployed, with the aim of reusing, and possibly adapting, its security policy. We illustrate our approach through a detailed smartphone ecosystem case study. Our results suggest that the scheme can provide users with a reasonably good policy that is consistent with the user's security preferences implicitly captured by policies already in place.

  6. Bootstrapping Security Policies for Wearable Apps Using Attributed Structural Graphs

    Directory of Open Access Journals (Sweden)

    Ana I. González-Tablas

    2016-05-01

    Full Text Available We address the problem of bootstrapping security and privacy policies for newly-deployed apps in wireless body area networks (WBAN composed of smartphones, sensors and other wearable devices. We introduce a framework to model such a WBAN as an undirected graph whose vertices correspond to devices, apps and app resources, while edges model structural relationships among them. This graph is then augmented with attributes capturing the features of each entity together with user-defined tags. We then adapt available graph-based similarity metrics to find the closest app to a new one to be deployed, with the aim of reusing, and possibly adapting, its security policy. We illustrate our approach through a detailed smartphone ecosystem case study. Our results suggest that the scheme can provide users with a reasonably good policy that is consistent with the user’s security preferences implicitly captured by policies already in place.

  7. Higgs Critical Exponents and Conformal Bootstrap in Four Dimensions

    CERN Document Server

    Antipin, Oleg; Sannino, Francesco

    2014-01-01

    Within a precise framework, we investigate relevant properties of composite operators emerging in nonsupersymmetric, four-dimensional gauge-Yukawa theories with interacting conformal fixed points. The theories investigated in this work are structurally similar to the standard model of particle interactions, but differ from the standard model by developing perturbative interacting fixed points. We investigate the physical properties of the singlet and the adjoint composite operators quadratic in the Higgs field. We show that, in the Veneziano limit, and at the highest known order in perturbation theory, the singlet sector decouples from the other operators. This fact allows us to test the numerical bootstrap constraints against precise four dimensional conformal field theoretical results.

  8. Measurement Axis Searching Model for Terrestrial Laser Scans Registration

    Directory of Open Access Journals (Sweden)

    Shaoxing Hu

    2016-01-01

    Full Text Available Nowadays, terrestrial Lidar scans can cover rather a large area; the point densities are strongly varied because of the line-of-sight measurement principle in potential overlaps with scans taken from different viewpoints. Most of the traditional methods focus on registration algorithm and ignore searching model. Sometimes the traditional methods are directly used to align two point clouds; a large critically unsolved problem of the large biases will be created in areas distant from the overlaps while the local overlaps are often aligned well. So a novel measurement axis searching model (MASM has been proposed in this paper. The method includes four steps: (1 the principal axis fitting, (2 the measurement axis generation, (3 low-high-precision search, and (4 result generation. The principal axis gives an orientation to the point cloud; the search scope is limited by the measurement axis. The point cloud orientation can be adjusted gradually until the achievement of the global optimum using low- and high-precision search. We perform some experiments with simulated point clouds and real terrestrial laser scans. The results of simulated point clouds have shown the processing steps of our method, and the results of real terrestrial laser scans have shown the sensitivity of the approach with respect to the indoor and outdoor scenes.

  9. Searches for Standard Model Higgs at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Cortavitarte, Rocio Vilar; /Cantabria Inst. of Phys.

    2007-11-01

    A summary of the latest results of Standard Model Higgs boson searches from CDF and D0 presented at the DIS 2007 conference is reported in this paper. All analyses presented use 1 fb{sup -1} of Tevatron data. The strategy of the different analyses is determined by the Higgs production mechanism and decay channel.

  10. Searches for Physics Beyond Standard Model at LHC with ATLAS

    CERN Document Server

    Soni, N; The ATLAS collaboration

    2013-01-01

    This contribution summarises some of the recent results on the searches for physics beyond the Standard Model using the pp-collision data collected at Large Hadron Collider (LHC) with ATLAS detector at centre-of-mass energy of sqrt{s} = 8 TeV. The search for supersymmetry (SUSY) is carried out in a large variety of production modes such as strong production of squarks and gluinos, weak production of sleptons and gauginos os production of massive long-lived particles through R-parity violation. No excess above the Standard Model background expectation is observed and exclusion limits are derived on the production of new physics. The results are interpreted as lower limits on sparticle masses in SUSY breaking scenarios. Searches for new exotic phenomena such as dark matter, large extra dimensions and black holes are also performed at ATLAS. As in the case of SUSY searches, no new exotic phenomena is observed and results are presented as upper limits on event yields from non-Standard-Model processes in a model i...

  11. Advertising and Consumer Search in a Duopoly Model

    NARCIS (Netherlands)

    M.C.W. Janssen (Maarten); M.C. Non (Marielle)

    2005-01-01

    textabstractWe consider a duopoly in a homogenous goods market where part of the consumers are ex ante uninformed about prices. Information can come through two different channels: advertising and sequential consumer search. The model is similar to that of Robert and Stahl (1993) with two major (and

  12. Combining candidate and document models for expert search

    NARCIS (Netherlands)

    K. Balog; M. de Rijke

    2008-01-01

    We describe our participation in the TREC 2008 Enterprise track and detail our language modeling-based approaches. For document search, our focus was on query expansion using profiles of top ranked experts and on document priors. We found that these techniques result in small, but noticeable improve

  13. Simplified Models for Dark Matter Searches at the LHC

    CERN Document Server

    Abdallah, Jalal; Arbey, Alexandre; Ashkenazi, Adi; Belyaev, Alexander; Berger, Joshua; Boehm, Celine; Boveia, Antonio; Brennan, Amelia; Brooke, Jim; Buchmueller, Oliver; Buckley, Matthew; Busoni, Giorgio; Calibbi, Lorenzo; Chauhan, Sushil; Daci, Nadir; Davies, Gavin; De Bruyn, Isabelle; de Jong, Paul; De Roeck, Albert; de Vries, Kees; del Re, Daniele; De Simone, Andrea; Di Simone, Andrea; Doglioni, Caterina; Dolan, Matthew; Dreiner, Herbi K.; Ellis, John; Eno, Sarah; Etzion, Erez; Fairbairn, Malcolm; Feldstein, Brian; Flaecher, Henning; Feng, Eric; Fox, Patrick; Genest, Marie-Hélène; Gouskos, Loukas; Gramling, Johanna; Haisch, Ulrich; Harnik, Roni; Hibbs, Anthony; Hoh, Siewyan; Hopkins, Walter; Ippolito, Valerio; Jacques, Thomas; Kahlhoefer, Felix; Khoze, Valentin V.; Kirk, Russell; Korn, Andreas; Kotov, Khristian; Kunori, Shuichi; Landsberg, Greg; Liem, Sebastian; Lin, Tongyan; Lowette, Steven; Lucas, Robyn; Malgeri, Luca; Malik, Sarah; McCabe, Christopher; Mete, Alaettin Serhan; Morgante, Enrico; Mrenna, Stephen; Nakahama, Yu; Newbold, Dave; Nordstrom, Karl; Pani, Priscilla; Papucci, Michele; Pataraia, Sophio; Penning, Bjoern; Pinna, Deborah; Polesello, Giacomo; Racco, Davide; Re, Emanuele; Riotto, Antonio Walter; Rizzo, Thomas; Salek, David; Sarkar, Subir; Schramm, Steven; Skubic, Patrick; Slone, Oren; Smirnov, Juri; Soreq, Yotam; Sumner, Timothy; Tait, Tim M.P.; Thomas, Marc; Tomalin, Ian; Tunnell, Christopher; Vichi, Alessandro; Volansky, Tomer; Weiner, Neal; West, Stephen M.; Wielers, Monika; Worm, Steven; Yavin, Itay; Zaldivar, Bryan; Zhou, Ning; Zurek, Kathryn

    2015-01-01

    This document outlines a set of simplified models for dark matter and its interactions with Standard Model particles. It is intended to summarize the main characteristics that these simplified models have when applied to dark matter searches at the LHC, and to provide a number of useful expressions for reference. The list of models includes both s-channel and t-channel scenarios. For s-channel, spin-0 and spin-1 mediation is discussed, and also realizations where the Higgs particle provides a portal between the dark and visible sectors. The guiding principles underpinning the proposed simplified models are spelled out, and some suggestions for implementation are presented.

  14. High Mass Standard Model Higgs searches at the Tevatron

    Directory of Open Access Journals (Sweden)

    Petridis Konstantinos A.

    2012-06-01

    Full Text Available We present the results of searches for the Standard Model Higgs boson decaying predominantly to W+W− pairs, at a center-of-mass energy of √s = 1.96 TeV, using up to 8.2 fb−1 of data collected with the CDF and D0 detectors at the Fermilab Tevatron collider. The analysis techniques and the various channels considered are discussed. These searches result in exclusions across the Higgs mass range of 156.5< mH <173.7 GeV for CDF and 161< mH <170 GeV for D0.

  15. Parameter Estimation of Photovoltaic Models via Cuckoo Search

    OpenAIRE

    Jieming Ma; Ting, T. O.; Ka Lok Man; Nan Zhang; Sheng-Uei Guan; Wong, Prudence W. H.

    2013-01-01

    Since conventional methods are incapable of estimating the parameters of Photovoltaic (PV) models with high accuracy, bioinspired algorithms have attracted significant attention in the last decade. Cuckoo Search (CS) is invented based on the inspiration of brood parasitic behavior of some cuckoo species in combination with the Lévy flight behavior. In this paper, a CS-based parameter estimation method is proposed to extract the parameters of single-diode models for commercial PV generators. S...

  16. Search for Flavoured Multiquarks in a Simple Bag Model

    CERN Document Server

    Zouzou, S

    1993-01-01

    We use a bag model to study flavoured mesonic $(Qq\\bar q\\bar q)$ and baryonic $({\\overline Q}qqqq)$ states, where one heavy quark $Q$ is associated with light quarks or antiquarks, and search for possible stable multiquarks. No bound state is found. However some states lie not too high above their dissociation threshold, suggesting the possibility of resonances, or perhaps bound states in improved models.

  17. Model independent search for Z'-boson signals

    OpenAIRE

    Gulov, A. V.; Skalozub, V. V.

    2009-01-01

    An approach to the model-independent searching for the Z' gauge boson as a virtual state in scattering processes is developed. It accounts for as a basic requirement the renormalizability of underlying unspecified in other respects model. This results in a set of relations between low energy couplings of Z' to fermions that reduces in an essential way the number of parameters to be fitted in experiments. On this ground the observables which uniquely pick out the Z' boson in leptonic processes...

  18. Spatial capture-recapture models for search-encounter data

    Science.gov (United States)

    Royle, J. Andrew; Kery, Marc; Guelat, Jerome

    2011-01-01

    1. Spatial capture–recapture models make use of auxiliary data on capture location to provide density estimates for animal populations. Previously, models have been developed primarily for fixed trap arrays which define the observable locations of individuals by a set of discrete points. 2. Here, we develop a class of models for 'search-encounter' data, i.e. for detections of recognizable individuals in continuous space, not restricted to trap locations. In our hierarchical model, detection probability is related to the average distance between individual location and the survey path. The locations are allowed to change over time owing to movements of individuals, and individual locations are related formally by a model describing individual activity or home range centre which is itself regarded as a latent variable in the model. We provide a Bayesian analysis of the model in WinBUGS, and develop a custom MCMC algorithm in the R language. 3. The model is applied to simulated data and to territory mapping data for the Willow Tit from the Swiss Breeding Bird Survey MHB. While the observed density was 15 territories per nominal 1 km2 plot of unknown effective sample area, the model produced a density estimate of 21∙12 territories per square km (95% posterior interval: 17–26). 4. Spatial capture–recapture models are relevant to virtually all animal population studies that seek to estimate population size or density, yet existing models have been proposed mainly for conventional sampling using arrays of traps. Our model for search-encounter data, where the spatial pattern of searching can be arbitrary and may change over occasions, greatly expands the scope and utility of spatial capture–recapture models.

  19. Model Independent Search For New Physics At The Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Choudalakis, Georgios; /MIT

    2008-05-01

    The Standard Model of elementary particles can not be the final theory. There are theoretical reasons to expect the appearance of new physics, possibly at the energy scale of few TeV. Several possible theories of new physics have been proposed, each with unknown probability to be confirmed. Instead of arbitrarily choosing to examine one of those theories, this thesis is about searching for any sign of new physics in a model-independent way. This search is performed at the Collider Detector at Fermilab (CDF). The Standard Model prediction is implemented in all final states simultaneously, and an array of statistical probes is employed to search for significant discrepancies between data and prediction. The probes are sensitive to overall population discrepancies, shape disagreements in distributions of kinematic quantities of final particles, excesses of events of large total transverse momentum, and local excesses of data expected from resonances due to new massive particles. The result of this search, first in 1 fb{sup -1} and then in 2 fb{sup -1}, is null, namely no considerable evidence of new physics was found.

  20. Model Independent Search For New Physics At The Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Choudalakis, Georgios [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2008-04-01

    The Standard Model of elementary particles can not be the final theory. There are theoretical reasons to expect the appearance of new physics, possibly at the energy scale of few TeV. Several possible theories of new physics have been proposed, each with unknown probability to be confirmed. Instead of arbitrarily choosing to examine one of those theories, this thesis is about searching for any sign of new physics in a model-independent way. This search is performed at the Collider Detector at Fermilab (CDF). The Standard Model prediction is implemented in all final states simultaneously, and an array of statistical probes is employed to search for significant discrepancies between data and prediction. The probes are sensitive to overall population discrepancies, shape disagreements in distributions of kinematic quantities of final particles, excesses of events of large total transverse momentum, and local excesses of data expected from resonances due to new massive particles. The result of this search, first in 1 fb-1 and then in 2 fb-1, is null, namely no considerable evidence of new physics was found.

  1. Learning web development with Bootstrap and AngularJS

    CERN Document Server

    Radford, Stephen

    2015-01-01

    Whether you know a little about Bootstrap or AngularJS, or you're a complete beginner, this book will enhance your capabilities in both frameworks and you'll build a fully functional web app. A working knowledge of HTML, CSS, and JavaScript is required to fully get to grips with Bootstrap and AngularJS.

  2. On bootstrap sample size in extreme value theory

    NARCIS (Netherlands)

    J.L. Geluk (Jaap); L.F.M. de Haan (Laurens)

    2002-01-01

    textabstractIt has been known for a long time that for bootstrapping the probability distribution of the maximum of a sample consistently, the bootstrap sample size needs to be of smaller order than the original sample size. See Jun Shao and Dongsheng Tu (1995), Ex. 3.9,p. 123. We show that the same

  3. Bootstrap Estimates of Standard Errors in Generalizability Theory

    Science.gov (United States)

    Tong, Ye; Brennan, Robert L.

    2007-01-01

    Estimating standard errors of estimated variance components has long been a challenging task in generalizability theory. Researchers have speculated about the potential applicability of the bootstrap for obtaining such estimates, but they have identified problems (especially bias) in using the bootstrap. Using Brennan's bias-correcting procedures…

  4. Using Commonly Available Software for Conducting Bootstrap Analyses.

    Science.gov (United States)

    Fan, Xitao

    Bootstrap analysis, both for nonparametric statistical inference and for describing sample results stability and replicability, has been gaining prominence among quantitative researchers in educational and psychological research. Procedurally, however, it is often quite a challenge for quantitative researchers to implement bootstrap analysis in…

  5. LEP Higgs boson searches beyond the standard model and minimum supersymmetric standard model

    Indian Academy of Sciences (India)

    Pauline Gagnon

    2004-03-01

    Ever since the center-of-mass energy was increased in 1995 above the $Z^{0}$ resonance, the four LEP experiments (ALEPH, DELPHI, OPAL and L3) have renewed their effort to search for the Higgs boson. Data taking ended in the year 2000 with about 130 pb-1 f data collected per experiment above 206 GeV in $e^{+} e^{-}$ collisions but the data analysis is still very active. Most recently, the wealth of theoretical models and predictions has stimulated new analyses and model interpretations which go beyond the standard model and minimal supersymmetric standard model. These include the searches for charged Higgs bosons, models with two Higgs field doublets, searches for ‘fermiophobic’ Higgs decay, invisible Higgs boson decays, decay-mode independent searches, and limits on Yukawa and anomalous Higgs couplings. I review the searches done by the four LEP experiments and present the LEP combined results when they exist.

  6. Neuronal trauma model: in search of Thanatos.

    Science.gov (United States)

    Cole, Kasie; Perez-Polo, J Regino

    2004-11-01

    Trauma to the nervous system triggers responses that include oxidative stress due to the generation of reactive oxygen species (ROS). DNA is a major macromolecular target of ROS, and ROS-induced DNA strand breaks activate poly(ADP-ribose)polymerase-1 (PARP-1). Upon activation PARP-1 uses NAD(+) as a substrate to catalyze the transfer of ADP-ribose subunits to a host of nuclear proteins. In the face of extensive DNA strand breaks, PARP-1 activation can lead to depletion of intracellular NAD(P)(H) pools, large decreases in ATP, that threaten cell survival. Accordingly, inhibition of PARP-1 activity after acute oxidative injury has been shown to increase cell survival. When NGF-differentiated PC12 cells, an in vitro neuronal model, are exposed to H(2)O(2) there is increased synthesis of poly ADP-ribose and decreases in intracellular NAD(P)(H) and ATP. Addition of the chemical PARP inhibitor 3-aminobenzamide (AB) prior to H(2)O(2) exposure blocks the synthesis of poly ADP-ribose and maintains intracellular NAD(P)(H) and ATP levels. H(2)O(2) injury is characterized by an immediate, necrotic cell death 2h after injury and a delayed apoptotic-like death 12-24h after injury. This apoptotic-like death is characterized by apoptotic membrane changes and apoptotic DNA fragmentation but is not associated with measurable caspase-3 activity. AB delays cell death beyond 24h and increases cell survival by approximately 25%. This protective effect is accompanied by significantly decreased necrosis and the apoptotic-like death associated with H(2)O(2) exposure. AB also restores caspase-3 which can be attributed to the activation of the upstream activator of caspase-3, caspase-9. Thus, the maintenance of intracellular ATP levels associated with PARP-1 inhibition shifts cell death from necrosis to apoptosis and from apoptosis to cell survival. Furthermore, the shift from necrosis to apoptosis may be explained, in part, by an energy-dependent activation of caspase-9. PMID:15465278

  7. Higgs critical exponents and conformal bootstrap in four dimensions

    Science.gov (United States)

    Antipin, Oleg; Mølgaard, Esben; Sannino, Francesco

    2015-06-01

    We investigate relevant properties of composite operators emerging in non-supersymmetric, four-dimensional gauge-Yukawa theories with interacting conformal fixed points within a precise framework. The theories investigated in this work are structurally similar to the standard model of particle interactions, but differ by developing perturbative interacting fixed points. We investigate the physical properties of the singlet and the adjoint composite operators quadratic in the Higgs field, and discover, via a direct computation, that the singlet anomalous dimension is substantially larger than the adjoint one. The numerical bootstrap results are, when possible, compared to our precise findings associated to the four dimensional conformal field theoretical results. To accomplish this, it was necessary to calculate explicitly the crossing symmetry relations for the global symmetry group SU( N ) × SU( N ).

  8. Semantic Models for Scalable Search in the Internet of Things

    Directory of Open Access Journals (Sweden)

    Dennis Pfisterer

    2013-03-01

    Full Text Available The Internet of Things is anticipated to connect billions of embedded devices equipped with sensors to perceive their surroundings. Thereby, the state of the real world will be available online and in real-time and can be combined with other data and services in the Internet to realize novel applications such as Smart Cities, Smart Grids, or Smart Healthcare. This requires an open representation of sensor data and scalable search over data from diverse sources including sensors. In this paper we show how the Semantic Web technologies RDF (an open semantic data format and SPARQL (a query language for RDF-encoded data can be used to address those challenges. In particular, we describe how prediction models can be employed for scalable sensor search, how these prediction models can be encoded as RDF, and how the models can be queried by means of SPARQL.

  9. An information search model for online social Networks - MOBIRSE

    Directory of Open Access Journals (Sweden)

    J. A. Astaiza

    2015-12-01

    Full Text Available Online Social Networks (OSNs have been gaining great importance among Internet users in recent years. These are sites where it is possible to meet people, publish, and share content in a way that is both easy and free of charge. As a result, the volume of information contained in these websites has grown exponentially, and web search has consequently become an important tool for users to easily find information relevant to their social networking objectives. Making use of ontologies and user profiles can make these searches more effective. This article presents a model for Information Retrieval in OSNs (MOBIRSE based on user profile and ontologies which aims to improve the relevance of retrieved information on these websites. The social network Facebook was chosen for a case study and as the instance for the proposed model. The model was validated using measures such as At-k Precision and Kappa statistics, to assess its efficiency.

  10. Model Search: Formalizing and Automating Constraint Solving in MDE Platforms

    Science.gov (United States)

    Kleiner, Mathias; Del Fabro, Marcos Didonet; Albert, Patrick

    Model Driven Engineering (MDE) and constraint programming (CP) have been widely used and combined in different applications. However, existing results are either ad-hoc, not fully integrated or manually executed. In this article, we present a formalization and an approach for automating constraint-based solving in a MDE platform. Our approach generalizes existing work by combining known MDE concepts with CP techniques into a single operation called model search. We present the theoretical basis for model search, as well as an automated process that details the involved operations. We validate our approach by comparing two implemented solutions (one based on Alloy/SAT, the other on OPL/CP), and by executing them over an academic use-case.

  11. A COMPARISON OF RESAMPLING TECHNIQUES WHEN PARAMETERS ARE ON A BOUNDARY: THE BOOTSTRAP, SUBSAMPLE BOOTSTRAP, AND SUBSAMPLE JACKKNIFE

    OpenAIRE

    Hilmer, Christiana E.; Holt, Matthew T.

    2000-01-01

    This paper compares the finite sample performance of subsample bootstrap and subsample jackknife techniques to the traditional bootstrap method when parameters are constrained to be on some boundary. To assess how these three methods perform in an empirical application, a negative semi-definite translog cost function is estimated using U.S. manufacturing data.

  12. Robust hashing with local models for approximate similarity search.

    Science.gov (United States)

    Song, Jingkuan; Yang, Yi; Li, Xuelong; Huang, Zi; Yang, Yang

    2014-07-01

    Similarity search plays an important role in many applications involving high-dimensional data. Due to the known dimensionality curse, the performance of most existing indexing structures degrades quickly as the feature dimensionality increases. Hashing methods, such as locality sensitive hashing (LSH) and its variants, have been widely used to achieve fast approximate similarity search by trading search quality for efficiency. However, most existing hashing methods make use of randomized algorithms to generate hash codes without considering the specific structural information in the data. In this paper, we propose a novel hashing method, namely, robust hashing with local models (RHLM), which learns a set of robust hash functions to map the high-dimensional data points into binary hash codes by effectively utilizing local structural information. In RHLM, for each individual data point in the training dataset, a local hashing model is learned and used to predict the hash codes of its neighboring data points. The local models from all the data points are globally aligned so that an optimal hash code can be assigned to each data point. After obtaining the hash codes of all the training data points, we design a robust method by employing l2,1 -norm minimization on the loss function to learn effective hash functions, which are then used to map each database point into its hash code. Given a query data point, the search process first maps it into the query hash code by the hash functions and then explores the buckets, which have similar hash codes to the query hash code. Extensive experimental results conducted on real-life datasets show that the proposed RHLM outperforms the state-of-the-art methods in terms of search quality and efficiency.

  13. Conformal bootstrap, universality and gravitational scattering

    Directory of Open Access Journals (Sweden)

    Steven Jackson

    2015-12-01

    Full Text Available We use the conformal bootstrap equations to study the non-perturbative gravitational scattering between infalling and outgoing particles in the vicinity of a black hole horizon in AdS. We focus on irrational 2D CFTs with large c and only Virasoro symmetry. The scattering process is described by the matrix element of two light operators (particles between two heavy states (BTZ black holes. We find that the operator algebra in this regime is (i universal and identical to that of Liouville CFT, and (ii takes the form of an exchange algebra, specified by an R-matrix that exactly matches the scattering amplitude of 2+1 gravity. The R-matrix is given by a quantum 6j-symbol and the scattering phase by the volume of a hyperbolic tetrahedron. We comment on the relevance of our results to scrambling and the holographic reconstruction of the bulk physics near black hole horizons.

  14. Conformal Bootstrap, Universality and Gravitational Scattering

    CERN Document Server

    Jackson, Steven; Verlinde, Herman

    2014-01-01

    We use the conformal bootstrap equations to study the non-perturbative gravitational scattering between infalling and outgoing particles in the vicinity of a black hole horizon in AdS. We focus on irrational 2D CFTs with large $c$, a sparse light spectrum and only Virasoro symmetry. The scattering process is described by the matrix element of two light operators (particles) between two heavy states (BTZ black holes). We find that the operator algebra in this regime is (i) universal and identical to that of Liouville CFT, and (ii) takes the form of an exchange algebra, specified by an R-matrix that exactly matches with the scattering amplitude of 2+1 gravity. The R-matrix is given by a quantum 6j-symbol and the scattering phase by the volume of a hyperbolic tetrahedron. We comment on the relevance of our results to scrambling and the holographic reconstruction of the bulk physics near black hole horizons.

  15. Optimum Binary Search Trees on the Hierarchical Memory Model

    CERN Document Server

    Thite, Shripad

    2008-01-01

    The Hierarchical Memory Model (HMM) of computation is similar to the standard Random Access Machine (RAM) model except that the HMM has a non-uniform memory organized in a hierarchy of levels numbered 1 through h. The cost of accessing a memory location increases with the level number, and accesses to memory locations belonging to the same level cost the same. Formally, the cost of a single access to the memory location at address a is given by m(a), where m: N -> N is the memory cost function, and the h distinct values of m model the different levels of the memory hierarchy. We study the problem of constructing and storing a binary search tree (BST) of minimum cost, over a set of keys, with probabilities for successful and unsuccessful searches, on the HMM with an arbitrary number of memory levels, and for the special case h=2. While the problem of constructing optimum binary search trees has been well studied for the standard RAM model, the additional parameter m for the HMM increases the combinatorial comp...

  16. Searches for Neutral Higgs Bosons in Extended Models

    CERN Document Server

    Abdallah, J; Adam, W; Adzic, P; Albrecht, T; Alderweireld, T; Alemany-Fernandez, R; Allmendinger, T; Allport, P P; Amaldi, Ugo; Amapane, N; Amato, S; Anashkin, E; Andreazza, A; Andringa, S; Anjos, N; Antilogus, P; Apel, W D; Arnoud, Y; Ask, S; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Ballestrero, A; Bambade, P; Barbier, R; Bardin, Dimitri Yuri; Barker, G J; Baroncelli, A; Battaglia, Marco; Baubillier, M; Becks, K H; Begalli, M; Behrmann, A; Ben-Haim, E; Benekos, N C; Benvenuti, Alberto C; Bérat, C; Berggren, M; Berntzon, L; Bertrand, D; Besançon, M; Besson, N; Bloch, D; Blom, M; Bluj, M; Bonesini, M; Boonekamp, M; Booth, P S L; Borisov, G; Botner, O; Bouquet, B; Bowcock, T J V; Boyko, I; Bracko, M; Brenner, R; Brodet, E; Brückman, P; Brunet, J M; Bugge, L; Buschmann, P; Calvi, M; Camporesi, T; Canale, V; Carena, F; Castro, N; Cavallo, F R; Chapkin, M M; Charpentier, P; Checchia, P; Chierici, R; Shlyapnikov, P; Chudoba, J; Chung, S U; Cieslik, K; Collins, P; Contri, R; Cosme, G; Cossutti, F; Costa, M J; Crennell, D J; Cuevas-Maestro, J; D'Hondt, J; Dalmau, J; Da Silva, T; Da Silva, W; Della Ricca, G; De Angelis, A; de Boer, Wim; De Clercq, C; De Lotto, B; De Maria, N; De Min, A; De Paula, L S; Di Ciaccio, L; Di Simone, A; Doroba, K; Drees, J; Dris, M; Eigen, G; Ekelöf, T J C; Ellert, M; Elsing, M; Espirito-Santo, M C; Fanourakis, G K; Fassouliotis, D; Feindt, M; Fernández, J; Ferrer, A; Ferro, F; Flagmeyer, U; Föth, H; Fokitis, E; Fulda-Quenzer, F; Fuster, J A; Gandelman, M; García, C; Gavillet, P; Gazis, E N; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; Graziani, E; Grosdidier, G; Grzelak, K; Guy, J; Haag, C; Hallgren, A; Hamacher, K; Hamilton, K; Haug, S; Hauler, F; Hedberg, V; Hennecke, M; Herr, H; Hoffman, J; Holmgren, S O; Holt, P J; Houlden, M A; Hultqvist, K; Jackson, J N; Jarlskog, G; Jarry, P; Jeans, D; Johansson, E K; Johansson, P D; Jonsson, P; Joram, C; Jungermann, L; Kapusta, F; Katsanevas, S; Katsoufis, E C; Kernel, G; Kersevan, B P; Kerzel, U; Kiiskinen, A P; King, B T; Kjaer, N J; Kluit, P; Kokkinias, P; Kourkoumelis, C; Kuznetsov, O; Krumshtein, Z; Kucharczyk, M; Lamsa, J; Leder, G; Ledroit, F; Leinonen, L; Leitner, R; Lemonne, J; Lepeltier, V; Lesiak, T; Liebig, W; Liko, D; Lipniacka, A; Lopes, J H; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J; Malek, A; Maltezos, S; Mandl, F; Marco, J; Marco, R; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Masik, J; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Mazzucato, F; Mazzucato, M; McNulty, R; Meroni, C; Migliore, E; Mitaroff, W A; Mjörnmark, U; Moa, T; Moch, M; Mönig, K; Monge, R; Montenegro, J; Moraes, D; Moreno, S; Morettini, P; Müller, U; Münich, K; Mulders, M; Mundim, L; Murray, W; Muryn, B; Myatt, G; Myklebust, T; Nassiakou, M; Navarria, Francesco Luigi; Nawrocki, K; Nicolaidou, R; Nikolenko, M; Oblakowska-Mucha, A; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, R; Österberg, K; Ouraou, A; Oyanguren, A; Paganoni, M; Paiano, S; Palacios, J P; Palka, H; Papadopoulou, T D; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Peralta, L; Perepelitsa, V F; Perrotta, A; Petrolini, A; Piedra, J; Pieri, L; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Poireau, V; Pol, M E; Polok, G; Pozdnyakov, V; Pukhaeva, N; Pullia, A; Rames, J; Read, A; Rebecchi, P; Rehn, J; Reid, D; Reinhardt, R; Renton, P B; Richard, F; Rídky, J; Rivero, M; Rodríguez, D; Romero, A; Ronchese, P; Roudeau, P; Rovelli, T; Ruhlmann-Kleider, V; Ryabtchikov, D; Sadovskii, A; Salmi, L; Salt, J; Sander, C; Savoy-Navarro, A; Schwickerath, U; Segar, A; Sekulin, R L; Siebel, M; Sissakian, A N; Smadja, G; Smirnova, O G; Sokolov, A; Sopczak, A; Sosnowski, R; Spassoff, Tz; Stanitzki, M; Stocchi, A; Strauss, J; Stugu, B; Szczekowski, M; Szeptycka, M; Szumlak, T; Tabarelli de Fatis, T; Taffard, A C; Tegenfeldt, F; Timmermans, J; Tkatchev, L G; Tobin, M; Todorovova, S; Tomé, B; Tonazzo, A; Tortosa, P; Travnicek, P; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Turluer, M L; Tyapkin, I A; Tyapkin, P; Tzamarias, S; Uvarov, V; Valenti, G; van Dam, P; Van Eldik, J; Van Lysebetten, A; Van Remortel, N; Van Vulpen, I; Vegni, G; Veloso, F; Venus, W; Verdier, P; Verzi, V; Vilanova, D; Vitale, L; Vrba, V; Wahlen, H; Washbrook, A J; Weiser, C; Wicke, D; Wickens, J; Wilkinson, G; Winter, M; Witek, M; Yushchenko, O P; Zalewska-Bak, A; Zalewski, P; Zavrtanik, D; Zhuravlov, V; Zimin, N I; Zintchenko, A; Zupan, M

    2004-01-01

    Searches for neutral Higgs bosons produced at LEP in association with Z bosons, in pairs and in the Yukawa process are presented in this paper. Higgs boson decays into b quarks, tau leptons, or other Higgs bosons are considered, giving rise to four-b, four-b+jets, six-b and four-tau final states, as well as mixed modes with b quarks and tau leptons. The whole mass domain kinematically accessible at LEP in these topologies is searched. The analysed data set covers both the LEP1 and LEP2 energy ranges and exploits most of the luminosity recorded by the DELPHI experiment. No convincing evidence for a signal is found, and results are presented in the form of mass-dependent upper bounds on coupling factors (in units of model-independent reference cross-sections) for all processes, allowing interpretation of the data in a large class of models.

  17. Wage Dispersion in the Search and Matching Model

    OpenAIRE

    Dale T. Mortensen

    2010-01-01

    Matched employer-employee data exhibits both wage and productivity dispersion across firms and suggest that a linear relationship holds between the average wage paid and a firm productivity. The purpose of this paper is to demonstrate that these facts can be explained by a search and matching model when firms are heterogenous with respect to productivity, are composed of many workers, and face diminishing returns to labor given the wage paid to identical workers is the solution to the Stole-Z...

  18. Properties of bootstrap tests for N-of-1 studies

    OpenAIRE

    Lin, Sharon Xiaowen; Morrison, Leanne; Smith, Peter; Hargood, Charlie; Weal, Mark; Yardley, Lucy

    2016-01-01

    N-of-1 study designs involve the collection and analysis of repeated measures data from an individual not using an intervention and using an intervention. This study explores the use of semi-parametric and parametric bootstrap tests in the analysis of N-of-1 studies under a single time series framework in the presence of autocorrelation. When the Type I error rates of bootstrap tests are compared to Wald tests, our results show that the bootstrap tests have more desirable properties. We compa...

  19. Searching for composite Higgs models at the LHC

    Science.gov (United States)

    Flacke, Thomas

    2016-07-01

    Composite Higgs models have the potential to provide a solution to the hierarchy problem and a dynamical explanation for the generation of the Higgs potential. They can be tested at the LHC as the new sector which underlies electroweak symmetry breaking must become strong in the TeV regime, which implies additional bound states beyond the Higgs. In this paper, we first discuss prospects and search strategies for top partners (and other quark partners) in the strongly coupled sector, which we study in an effective field theory setup. In the second part of the proceedings, we go beyond the effective field theory approach. We discuss potential UV embeddings for composite Higgs models which contain a Higgs as well as top partners. We show that in all of these models, additional pseudo-Nambu-Goldstone bosons beyond the Higgs are present. In particular, all of the models contain a pseudoscalar which couples to the Standard Model gauge fields through Wess-Zumino-Witten terms, providing a prime candidate for a di-boson (including a di-photon) resonance. The models also contain colored pNGBs which can be searched for at the LHC.

  20. Constraints on Z' models from LHC dijet searches

    CERN Document Server

    Fairbairn, Malcolm; Kahlhoefer, Felix; Tunney, Patrick

    2016-01-01

    We analyse a combination of ATLAS and CMS searches for dijet resonances at run I and run II, presenting the results in a way that can be easily applied to a generic Z' model. As an illustrative example, we consider a simple model of a Z' coupling to quarks and dark matter. We first study a benchmark case with fixed couplings and then focus on the assumption that the Z' is responsible for setting the dark matter relic abundance. Dijet constraints place significant bounds on this scenario, allowing us to narrow down the allowed range of dark matter masses for given Z' mass and width.

  1. Characterizing economic trends by Bayesian stochastic model specification search

    DEFF Research Database (Denmark)

    Grassi, Stefano; Proietti, Tommaso

    We extend a recently proposed Bayesian model selection technique, known as stochastic model specification search, for characterising the nature of the trend in macroeconomic time series. In particular, we focus on autoregressive models with possibly time-varying intercept and slope and decide...... on whether their parameters are fixed or evolutive. Stochastic model specification is carried out to discriminate two alternative hypotheses concerning the generation of trends: the trend-stationary hypothesis, on the one hand, for which the trend is a deterministic function of time and the short run...... the traditional Nelson and Plosser dataset. The broad conclusion is that most series are better represented by autoregressive models with time-invariant intercept and slope and coefficients that are close to boundary of the stationarity region. The posterior distribution of the autoregressive parameters...

  2. Variance estimation in neutron coincidence counting using the bootstrap method

    Energy Technology Data Exchange (ETDEWEB)

    Dubi, C., E-mail: chendb331@gmail.com [Physics Department, Nuclear Research Center of the Negev, P.O.B. 9001 Beer Sheva (Israel); Ocherashvilli, A.; Ettegui, H. [Physics Department, Nuclear Research Center of the Negev, P.O.B. 9001 Beer Sheva (Israel); Pedersen, B. [Nuclear Security Unit, Institute for Transuranium Elements, Via E. Fermi, 2749 JRC, Ispra (Italy)

    2015-09-11

    In the study, we demonstrate the implementation of the “bootstrap” method for a reliable estimation of the statistical error in Neutron Multiplicity Counting (NMC) on plutonium samples. The “bootstrap” method estimates the variance of a measurement through a re-sampling process, in which a large number of pseudo-samples are generated, from which the so-called bootstrap distribution is generated. The outline of the present study is to give a full description of the bootstrapping procedure, and to validate, through experimental results, the reliability of the estimated variance. Results indicate both a very good agreement between the measured variance and the variance obtained through the bootstrap method, and a robustness of the method with respect to the duration of the measurement and the bootstrap parameters.

  3. Filter and modified stepwedge bootstrap sensitometry in medical radiography

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Akira

    1988-05-01

    Two new bootstrap methods for determining characteristic curves of radiographic screen/film systems are presented : filter bootstrap sensitometry and modified stepwedge bootstrap sensitometry. Both are intensity-scale sensitometries since the radiation intensity can be varied through use of a combination of inverse square and metal filters. Characteristic curves obtained by these methods are compared with those from screen/film systems using inverse square sensitometry as a reference standard of accuracy. The precision of all three methods is better than +- 2 % with agreement among generally being within 3 % over the useful density range. By these bootstrap methods, it is possible to obtain characteristic curves agreeing well with those using the inverse square method for a relatively short distance, and make radiographic sensitometry practical and convenient at most medical institutions.

  4. Bootstrapping pre-averaged realized volatility under market microstructure noise

    DEFF Research Database (Denmark)

    Hounyo, Ulrich; Goncalves, Sílvia; Meddahi, Nour

    The main contribution of this paper is to propose a bootstrap method for inference on integrated volatility based on the pre-averaging approach of Jacod et al. (2009), where the pre-averaging is done over all possible overlapping blocks of consecutive observations. The overlapping nature of the pre......-averaged returns implies that these are kn-dependent with kn growing slowly with the sample size n. This motivates the application of a blockwise bootstrap method. We show that the "blocks of blocks" bootstrap method suggested by Politis and Romano (1992) (and further studied by Bühlmann and Künsch (1995)) is...... valid only when volatility is constant. The failure of the blocks of blocks bootstrap is due to the heterogeneity of the squared pre-averaged returns when volatility is stochastic. To preserve both the dependence and the heterogeneity of squared pre-averaged returns, we propose a novel procedure that...

  5. 'Bootstrap' Configuration for Multistage Pulse-Tube Coolers

    Science.gov (United States)

    Nguyen, Bich; Nguyen, Lauren

    2008-01-01

    A bootstrap configuration has been proposed for multistage pulse-tube coolers that, for instance, provide final-stage cooling to temperatures as low as 20 K. The bootstrap configuration supplants the conventional configuration, in which customarily the warm heat exchangers of all stages reject heat at ambient temperature. In the bootstrap configuration, the warm heat exchanger, the inertance tube, and the reservoir of each stage would be thermally anchored to the cold heat exchanger of the next warmer stage. The bootstrapped configuration is superior to the conventional setup, in some cases increasing the 20 K cooler's coefficient of performance two-fold over that of an otherwise equivalent conventional layout. The increased efficiency could translate into less power consumption, less cooler mass, and/or lower cost for a given amount of cooling.

  6. On the range of validity of the autoregressive sieve bootstrap

    CERN Document Server

    Kreiss, Jens-Peter; Politis, Dimitris N; 10.1214/11-AOS900

    2012-01-01

    We explore the limits of the autoregressive (AR) sieve bootstrap, and show that its applicability extends well beyond the realm of linear time series as has been previously thought. In particular, for appropriate statistics, the AR-sieve bootstrap is valid for stationary processes possessing a general Wold-type autoregressive representation with respect to a white noise; in essence, this includes all stationary, purely nondeterministic processes, whose spectral density is everywhere positive. Our main theorem provides a simple and effective tool in assessing whether the AR-sieve bootstrap is asymptotically valid in any given situation. In effect, the large-sample distribution of the statistic in question must only depend on the first and second order moments of the process; prominent examples include the sample mean and the spectral density. As a counterexample, we show how the AR-sieve bootstrap is not always valid for the sample autocovariance even when the underlying process is linear.

  7. Relevance feedback and query expansion for searching the web: a model for searching a digital library

    OpenAIRE

    Alan F. SMEATON; Crimmins, Francis

    1997-01-01

    A fully operational large scale digital library is likely to be based on a distributed architecture and because of this it is likely that a number of independent search engines may be used to index different overlapping portions of the entire contents of the library. In any case, different media, text, audio, image, etc., will be indexed for retrieval by different search engines so techniques which provide a coherent and unified search over a suite of underlying independent search engines are...

  8. Subspaces indexing model on Grassmann manifold for image search.

    Science.gov (United States)

    Wang, Xinchao; Li, Zhu; Tao, Dacheng

    2011-09-01

    Conventional linear subspace learning methods like principal component analysis (PCA), linear discriminant analysis (LDA) derive subspaces from the whole data set. These approaches have limitations in the sense that they are linear while the data distribution we are trying to model is typically nonlinear. Moreover, these algorithms fail to incorporate local variations of the intrinsic sample distribution manifold. Therefore, these algorithms are ineffective when applied on large scale datasets. Kernel versions of these approaches can alleviate the problem to certain degree but face a serious computational challenge when data set is large, where the computing involves Eigen/QP problems of size N × N. When N is large, kernel versions are not computationally practical. To tackle the aforementioned problems and improve recognition/searching performance, especially on large scale image datasets, we propose a novel local subspace indexing model for image search termed Subspace Indexing Model on Grassmann Manifold (SIM-GM). SIM-GM partitions the global space into local patches with a hierarchical structure; the global model is, therefore, approximated by piece-wise linear local subspace models. By further applying the Grassmann manifold distance, SIM-GM is able to organize localized models into a hierarchy of indexed structure, and allow fast query selection of the optimal ones for classification. Our proposed SIM-GM enjoys a number of merits: 1) it is able to deal with a large number of training samples efficiently; 2) it is a query-driven approach, i.e., it is able to return an effective local space model, so the recognition performance could be significantly improved; 3) it is a common framework, which can incorporate many learning algorithms. Theoretical analysis and extensive experimental results confirm the validity of this model.

  9. On the range of validity of the autoregressive sieve bootstrap

    OpenAIRE

    Kreiss, Jens-Peter; Paparoditis, Efstathios; Politis, Dimitris N.

    2012-01-01

    We explore the limits of the autoregressive (AR) sieve bootstrap, and show that its applicability extends well beyond the realm of linear time series as has been previously thought. In particular, for appropriate statistics, the AR-sieve bootstrap is valid for stationary processes possessing a general Wold-type autoregressive representation with respect to a white noise; in essence, this includes all stationary, purely nondeterministic processes, whose spectral density is everywhere positive....

  10. Bootstrap transition to high beta equilibrium in helical system

    International Nuclear Information System (INIS)

    It is shown theoretically and computationally that helical magnetic field, produced by continuous winding helical coils and without the toroidal coil, can sustain MHD stable high beta plasma. Pressure driven toroidal current (bootstrap current) cancels the external magnetic field and reduces the MHD potential energy, depending on the plasma beta values. Ramp-up of heating power input induces bootstrap transition to higher beta plasmas with flat-top pressure profiles. Helical pitch parameter dependence of MHD stability is analyzed. (author)

  11. Bootstrapping the statistical uncertainties of NN scattering data

    CERN Document Server

    Perez, R Navarro; Arriola, E Ruiz

    2014-01-01

    We use the Monte Carlo bootstrap as a method to simulate pp and np scattering data below pion production threshold from an initial set of over 6700 experimental mutually $3\\sigma$ consistent data. We compare the results of the bootstrap, with 1020 statistically generated samples of the full database, with the standard covariance matrix method of error propagation. No significant differences in scattering observables and phase shifts are found. This suggests alternative strategies for propagating errors of nuclear forces in nuclear structure calculations.

  12. BOOTSTRAP-BASED STATISTICAL THRESHOLDING FOR MEG SOURCE RECONSTRUCTION IMAGES

    OpenAIRE

    Sekihara, Kensuke; Sahani, Maneesh; Nagarajan, Srikantan S.

    2004-01-01

    This paper proposes a bootstrap-based statistical method for extracting target source activities from MEG/EEG source reconstruction results. The method requires measurements in a control condition, which contains only non-target source activities. The method derives, at each pixel location, an empirical probability distribution of the non-target source activity using bootstrapped reconstruction obtained from the control period. The statistical threshold that can extract the target source acti...

  13. Conformal Collider Physics from the Lightcone Bootstrap

    CERN Document Server

    Li, Daliang; Poland, David

    2015-01-01

    We analytically study the lightcone limit of the conformal bootstrap equations for 4-point functions containing global symmetry currents and the stress tensor in 3d CFTs. We show that the contribution of the stress tensor to the anomalous dimensions of large spin double-twist states is negative if and only if the conformal collider physics bounds are satisfied. In the context of AdS/CFT these results indicate a relation between the attractiveness of AdS gravity and positivity of the CFT energy flux. We also study the contribution of non-Abelian conserved currents to the anomalous dimensions of double-twist operators, corresponding to the gauge binding energy of 2-particle states in AdS. We show that the representation of the double-twist state determines the sign of the gauge binding energy if and only if the coefficient appearing in the current 3-point function satisfies a similar bound, which is equivalent to an upper bound on the charge flux asymmetry of the CFT.

  14. Control of bootstrap current in the pedestal region of tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Shaing, K. C. [Institute for Space and Plasma Sciences, National Cheng Kung University, Tainan City 70101, Taiwan (China); Department of Engineering Physics, University of Wisconsin, Madison, Wisconsin 53796 (United States); Lai, A. L. [Institute for Space and Plasma Sciences, National Cheng Kung University, Tainan City 70101, Taiwan (China)

    2013-12-15

    The high confinement mode (H-mode) plasmas in the pedestal region of tokamaks are characterized by steep gradient of the radial electric field, and sonic poloidal U{sub p,m} flow that consists of poloidal components of the E×B flow and the plasma flow velocity that is parallel to the magnetic field B. Here, E is the electric field. The bootstrap current that is important for the equilibrium, and stability of the pedestal of H-mode plasmas is shown to have an expression different from that in the conventional theory. In the limit where ‖U{sub p,m}‖≫ 1, the bootstrap current is driven by the electron temperature gradient and inductive electric field fundamentally different from that in the conventional theory. The bootstrap current in the pedestal region can be controlled through manipulating U{sub p,m} and the gradient of the radial electric. This, in turn, can control plasma stability such as edge-localized modes. Quantitative evaluations of various coefficients are shown to illustrate that the bootstrap current remains finite when ‖U{sub p,m}‖ approaches infinite and to provide indications how to control the bootstrap current. Approximate analytic expressions for viscous coefficients that join results in the banana and plateau-Pfirsch-Schluter regimes are presented to facilitate bootstrap and neoclassical transport simulations in the pedestal region.

  15. Central Limit Theorem and bootstrap procedure for Wasserstein's variations with application to structural relationships between distributions

    OpenAIRE

    Del Barrio, Eustasio; Lescornel, Hélène; Loubes, Jean-Michel

    2016-01-01

    Wasserstein barycenters and variance-like criterion using Wasserstein distance are used in many problems to analyze the homo-geneity of collections of distributions and structural relationships between the observations. We propose the estimation of the quantiles of the empirical process of the Wasserstein's variation using a bootstrap procedure. Then we use these results for statistical inference on a distribution registration model for general deformation functions. The tests are based on th...

  16. Convergence properties of weighted particle islands with application to the double bootstrap algorithm

    OpenAIRE

    Vergé, Christelle; Del Moral, Pierre; Moulines, Eric; Olsson, Jimmy

    2014-01-01

    Particle island models (Verg\\'e et al., 2013) provide a means of parallelization of sequential Monte Carlo methods, and in this paper we present novel convergence results for algorithms of this sort. In particular we establish a central limit theorem - as the number of islands and the common size of the islands tend jointly to infinity - of the double bootstrap algorithm with possibly adaptive selection on the island level. For this purpose we introduce a notion of archipelagos of weighted is...

  17. On the Friedman Rule in Search Models with Divisible Money

    OpenAIRE

    Aleksander Berentsen; Guillaume Rocheteau

    2003-01-01

    "with Divisible Money *nAleksander Berentsen†nEconomics Department (WWZ), University of Basel, SwitzerlandnGuillaume Rocheteau‡nSchool of Economics, Australian National University, AustralianApril 14th, 2003nAbstractnThis paper studies the validity of the Friedman rule in a search model with divisi-blenmoney and divisible goods where the terms of trades are determined endogenously.nWe show that ex post bargaining generates a holdup problem similar to the one em-phasizednin the labou...

  18. Searches for the standard model Higgs boson at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Dorigo, Tommaso; /Padua U.

    2005-05-01

    The CDF and D0 experiments at the Tevatron have searched for the Standard Model Higgs boson in data collected between 2001 and 2004. Upper limits have been placed on the production cross section times branching ratio to b{bar b} pairs or W{sup +}W{sup -} pairs as a function of the Higgs boson mass. projections indicate that the Tevatron experiments have a chance of discovering a M{sub H} = 115 GeV Higgs with the total dataset foreseen by 2009, or excluding it at 95% C.L. up to a mass of 135 GeV.

  19. Search for a lighter Higgs in Two Higgs Doublet Models

    CERN Document Server

    Cacciapaglia, Giacomo; Gascon, Suzanne; Corre, Solene Le; Lethuillier, Morgan; Tao, Junquan

    2016-01-01

    We consider present constraints on two Higgs doublet models, both from the LHC at Run 1 and from other sources in order to explore the possibility of constraining a neutral scalar or pseudoscalar particle lighter than the 125 GeV Higgs boson. Contrary to naive expectations, such a lighter particle is not yet completely excluded by present data. We show with a simplified analysis that some new constraints could be obtained at the LHC if such a search is performed by the experimental collaborations.

  20. Interpretation of searches for supersymmetry with simplified models

    OpenAIRE

    Chatrchyan, S.; Brochero Cifuentes, J. A.; Cabrillo, I. J.(Instituto de Física de Cantabria (IFCA), CSIC-Universidad de Cantabria, Santander, Spain); Calderón-Urrea, Alejandro; Chuang, S. H.; Duarte Campderros, J.; Felcini, M.; Fernández, M; Gómez, G.; González Sánchez, J.; Graziano, A.; Jorda, C; López Virto, A.; Marco, Jesús; Marco, Rafael

    2013-01-01

    The results of searches for supersymmetry by the CMS experiment are interpreted in the framework of simplified models. The results are based on data corresponding to an integrated luminosity of 4.73 to 4.98 fb-1. The data were collected at the LHC in proton-proton collisions at a center-of-mass energy of 7 TeV. This paper describes the method of interpretation and provides upper limits on the product of the production cross section and branching fraction as a function of new particle masses f...

  1. In Search Of The Standard Model Higgs Boson

    CERN Document Server

    http://inspirehep.net/record/666184/files/fermilab-thesis-2004-35.PDF, R

    2002-01-01

    A search for the Standard Model Higgs boson is conducted using data from the L3 detector at CERN's LEP collider during the year 2000. The integrated luminosity collected was 217.4 pb−1 of electron-positron collisions at center-of-mass energies from 200 to 209 GeV. Presented here is a search for e+ e− → hZ, where the Higgs decays into b quarks and the Z boson decays into undetected neutrinos. Also presented are combined results from the other L3 channels. The L3 combined results are consistent with the Standard Model background. Preliminary results from the LEP-wide combination are also shown. The lower limit on the Standard Model Higgs mass is found to be mh>114.1GeV at95%C.L. In the LEP combination, an excess of data events is observed near mh ∼ 115.6 GeV. Whether this is due to a statistical fluctuation or to Higgs production cannot be determined from the available set of data.

  2. Millennial Students' Mental Models of Search: Implications for Academic Librarians and Database Developers

    Science.gov (United States)

    Holman, Lucy

    2011-01-01

    Today's students exhibit generational differences in the way they search for information. Observations of first-year students revealed a proclivity for simple keyword or phrases searches with frequent misspellings and incorrect logic. Although no students had strong mental models of search mechanisms, those with stronger models did construct more…

  3. Interpretation of searches for supersymmetry with simplified models

    CERN Document Server

    Chatrchyan, Serguei; Sirunyan, Albert M; Tumasyan, Armen; Adam, Wolfgang; Aguilo, Ernest; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kiesenhofer, Wolfgang; Knünz, Valentin; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Mikulec, Ivan; Pernicka, Manfred; Rabady, Dinyar; Rahbaran, Babak; Rohringer, Christine; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Taurok, Anton; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Bansal, Monika; Bansal, Sunil; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Luyckx, Sten; Mucibello, Luca; Ochesanu, Silvia; Roland, Benoit; Rougny, Romain; Selvaggi, Michele; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Gonzalez Suarez, Rebeca; Kalogeropoulos, Alexis; Maes, Michael; Olbrechts, Annik; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Clerbaux, Barbara; De Lentdecker, Gilles; Dero, Vincent; Gay, Arnaud; Hreus, Tomas; Léonard, Alexandre; Marage, Pierre Edouard; Mohammadi, Abdollah; Reis, Thomas; Thomas, Laurent; Vander Velde, Catherine; Vanlaer, Pascal; Wang, Jian; Adler, Volker; Beernaert, Kelly; Cimmino, Anna; Costantini, Silvia; Garcia, Guillaume; Grunewald, Martin; Klein, Benjamin; Lellouch, Jérémie; Marinov, Andrey; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Ryckbosch, Dirk; Strobbe, Nadja; Thyssen, Filip; Tytgat, Michael; Walsh, Sinead; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Bruno, Giacomo; Castello, Roberto; Ceard, Ludivine; Delaere, Christophe; Du Pree, Tristan; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Lemaitre, Vincent; Liao, Junhui; Militaru, Otilia; Nuttens, Claude; Pagano, Davide; Pin, Arnaud; Piotrzkowski, Krzysztof; Vizan Garcia, Jesus Manuel; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Hammad, Gregory Habib; Alves, Gilvan; Correa Martins Junior, Marcos; Martins, Thiago; Pol, Maria Elena; Henrique Gomes E Souza, Moacyr; Aldá Júnior, Walter Luiz; Carvalho, Wagner; Custódio, Analu; Da Costa, Eliza Melo; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Malbouisson, Helena; Malek, Magdalena; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Soares Jorge, Luana; Sznajder, Andre; Vilela Pereira, Antonio; Souza Dos Anjos, Tiago; Bernardes, Cesar Augusto; De Almeida Dias, Flavia; Tomei, Thiago; De Moraes Gregores, Eduardo; Lagana, Caio; Da Cunha Marinho, Franciole; Mercadante, Pedro G; Novaes, Sergio F; Padula, Sandra; Genchev, Vladimir; Iaydjiev, Plamen; Piperov, Stefan; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Tcholakov, Vanio; Trayanov, Rumen; Vutova, Mariana; Dimitrov, Anton; Hadjiiska, Roumyana; Kozhuharov, Venelin; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Jiang, Chun-Hua; Liang, Dong; Liang, Song; Meng, Xiangwei; Tao, Junquan; Wang, Jian; Wang, Xianyou; Wang, Zheng; Xiao, Hong; Xu, Ming; Zang, Jingjing; Zhang, Zhen; Asawatangtrakuldee, Chayanit; Ban, Yong; Guo, Yifei; Li, Wenbo; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Teng, Haiyun; Wang, Dayong; Zhang, Linlin; Zou, Wei; Avila, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Osorio Oliveros, Andres Felipe; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Plestina, Roko; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Duric, Senka; Kadija, Kreso; Luetic, Jelena; Mekterovic, Darko; Morovic, Srecko; Attikis, Alexandros; Galanti, Mario; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Finger, Miroslav; Finger Jr, Michael; Assran, Yasser; Elgammal, Sherif; Ellithi Kamel, Ali; Mahmoud, Mohammed; Mahrous, Ayman; Radi, Amr; Kadastik, Mario; Müntel, Mait; Raidal, Martti; Rebane, Liis; Tiko, Andres; Eerola, Paula; Fedi, Giacomo; Voutilainen, Mikko; Härkönen, Jaakko; Heikkinen, Mika Aatos; Karimäki, Veikko; Kinnunen, Ritva; Kortelainen, Matti J; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Peltola, Timo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Ungaro, Donatella; Wendland, Lauri; Banzuzi, Kukka; Karjalainen, Ahti; Korpela, Arja; Tuuva, Tuure; Besancon, Marc; Choudhury, Somnath; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Ferri, Federico; Ganjour, Serguei; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Malcles, Julie; Millischer, Laurent; Nayak, Aruna; Rander, John; Rosowsky, André; Titov, Maksym; Baffioni, Stephanie; Beaudette, Florian; Benhabib, Lamia; Bianchini, Lorenzo; Bluj, Michal; Busson, Philippe; Charlot, Claude; Daci, Nadir; Dahms, Torsten; Dalchenko, Mykhailo; Dobrzynski, Ludwik; Florent, Alice; Granier de Cassagnac, Raphael; Haguenauer, Maurice; Miné, Philippe; Mironov, Camelia; Naranjo, Ivo Nicolas; Nguyen, Matthew; Ochando, Christophe; Paganini, Pascal; Sabes, David; Salerno, Roberto; Sirois, Yves; Veelken, Christian; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Bloch, Daniel; Bodin, David; Brom, Jean-Marie; Cardaci, Marco; Chabert, Eric Christian; Collard, Caroline; Conte, Eric; Drouhin, Frédéric; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Juillot, Pierre; Le Bihan, Anne-Catherine; Van Hove, Pierre; Fassi, Farida; Mercier, Damien; Beauceron, Stephanie; Beaupere, Nicolas; Bondu, Olivier; Boudoul, Gaelle; Brochet, Sébastien; Chasserat, Julien; Chierici, Roberto; Contardo, Didier; Depasse, Pierre; El Mamouni, Houmani; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Ille, Bernard; Kurca, Tibor; Lethuillier, Morgan; Mirabito, Laurent; Perries, Stephane; Sgandurra, Louis; Sordini, Viola; Tschudi, Yohann; Verdier, Patrice; Viret, Sébastien; Tsamalaidze, Zviad; Autermann, Christian; Beranek, Sarah; Calpas, Betty; Edelhoff, Matthias; Feld, Lutz; Heracleous, Natalie; Hindrichs, Otto; Jussen, Ruediger; Klein, Katja; Merz, Jennifer; Ostapchuk, Andrey; Perieanu, Adrian; Raupach, Frank; Sammet, Jan; Schael, Stefan; Sprenger, Daniel; Weber, Hendrik; Wittmer, Bruno; Zhukov, Valery; Ata, Metin; Caudron, Julien; Dietz-Laursonn, Erik; Duchardt, Deborah; Erdmann, Martin; Fischer, Robert; Güth, Andreas; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Klingebiel, Dennis; Kreuzer, Peter; Merschmeyer, Markus; Meyer, Arnd; Olschewski, Mark; Papacz, Paul; Pieta, Holger; Reithler, Hans; Schmitz, Stefan Antonius; Sonnenschein, Lars; Steggemann, Jan; Teyssier, Daniel; Thüer, Sebastian; Weber, Martin; Bontenackels, Michael; Cherepanov, Vladimir; Erdogan, Yusuf; Flügge, Günter; Geenen, Heiko; Geisler, Matthias; Haj Ahmad, Wael; Hoehle, Felix; Kargoll, Bastian; Kress, Thomas; Kuessel, Yvonne; Lingemann, Joschka; Nowack, Andreas; Perchalla, Lars; Pooth, Oliver; Sauerland, Philip; Stahl, Achim; Aldaya Martin, Maria; Behr, Joerg; Behrenhoff, Wolf; Behrens, Ulf; Bergholz, Matthias; Bethani, Agni; Borras, Kerstin; Burgmeier, Armin; Cakir, Altan; Calligaris, Luigi; Campbell, Alan; Castro, Elena; Costanza, Francesco; Dammann, Dirk; Diez Pardos, Carmen; Eckerlin, Guenter; Eckstein, Doris; Flucke, Gero; Geiser, Achim; Glushkov, Ivan; Gunnellini, Paolo; Habib, Shiraz; Hauk, Johannes; Hellwig, Gregor; Jung, Hannes; Kasemann, Matthias; Katsas, Panagiotis; Kleinwort, Claus; Kluge, Hannelies; Knutsson, Albert; Krämer, Mira; Krücker, Dirk; Kuznetsova, Ekaterina; Lange, Wolfgang; Leonard, Jessica; Lohmann, Wolfgang; Lutz, Benjamin; Mankel, Rainer; Marfin, Ihar; Marienfeld, Markus; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mnich, Joachim; Mussgiller, Andreas; Naumann-Emme, Sebastian; Novgorodova, Olga; Olzem, Jan; Perrey, Hanno; Petrukhin, Alexey; Pitzl, Daniel; Raspereza, Alexei; Ribeiro Cipriano, Pedro M; Riedl, Caroline; Ron, Elias; Rosin, Michele; Salfeld-Nebgen, Jakob; Schmidt, Ringo; Schoerner-Sadenius, Thomas; Sen, Niladri; Spiridonov, Alexander; Stein, Matthias; Walsh, Roberval; Wissing, Christoph; Blobel, Volker; Enderle, Holger; Erfle, Joachim; Gebbert, Ulla; Görner, Martin; Gosselink, Martijn; Haller, Johannes; Hermanns, Thomas; Höing, Rebekka Sophie; Kaschube, Kolja; Kaussen, Gordon; Kirschenmann, Henning; Klanner, Robert; Lange, Jörn; Nowak, Friederike; Peiffer, Thomas; Pietsch, Niklas; Rathjens, Denis; Sander, Christian; Schettler, Hannes; Schleper, Peter; Schlieckau, Eike; Schmidt, Alexander; Schröder, Matthias; Schum, Torben; Seidel, Markus; Sibille, Jennifer; Sola, Valentina; Stadie, Hartmut; Steinbrück, Georg; Thomsen, Jan; Vanelderen, Lukas; Barth, Christian; Berger, Joram; Böser, Christian; Chwalek, Thorsten; De Boer, Wim; Descroix, Alexis; Dierlamm, Alexander; Feindt, Michael; Guthoff, Moritz; Hackstein, Christoph; Hartmann, Frank; Hauth, Thomas; Heinrich, Michael; Held, Hauke; Hoffmann, Karl-Heinz; Husemann, Ulrich; Katkov, Igor; Komaragiri, Jyothsna Rani; Lobelle Pardo, Patricia; Martschei, Daniel; Mueller, Steffen; Müller, Thomas; Niegel, Martin; Nürnberg, Andreas; Oberst, Oliver; Oehler, Andreas; Ott, Jochen; Quast, Gunter; Rabbertz, Klaus; Ratnikov, Fedor; Ratnikova, Natalia; Röcker, Steffen; Schilling, Frank-Peter; Schott, Gregory; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Troendle, Daniel; Ulrich, Ralf; Wagner-Kuhr, Jeannine; Wayand, Stefan; Weiler, Thomas; Zeise, Manuel; Anagnostou, Georgios; Daskalakis, Georgios; Geralis, Theodoros; Kesisoglou, Stilianos; Kyriakis, Aristotelis; Loukas, Demetrios; Manolakos, Ioannis; Markou, Athanasios; Markou, Christos; Ntomari, Eleni; Gouskos, Loukas; Mertzimekis, Theodoros; Panagiotou, Apostolos; Saoulidou, Niki; Evangelou, Ioannis; Foudas, Costas; Kokkas, Panagiotis; Manthos, Nikolaos; Papadopoulos, Ioannis; Patras, Vaios; Bencze, Gyorgy; Hajdu, Csaba; Hidas, Pàl; Horvath, Dezso; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Beni, Noemi; Czellar, Sandor; Molnar, Jozsef; Palinkas, Jozsef; Szillasi, Zoltan; Karancsi, János; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Beri, Suman Bala; Bhatnagar, Vipin; Dhingra, Nitish; Gupta, Ruchi; Kaur, Manjit; Mehta, Manuk Zubin; Nishu, Nishu; Saini, Lovedeep Kaur; Sharma, Archana; Singh, Jasbir; Kumar, Ashok; Kumar, Arun; Ahuja, Sudha; Bhardwaj, Ashutosh; Choudhary, Brajesh C; Malhotra, Shivali; Naimuddin, Md; Ranjan, Kirti; Sharma, Varun; Shivpuri, Ram Krishen; Banerjee, Sunanda; Bhattacharya, Satyaki; Dutta, Suchandra; Gomber, Bhawna; Jain, Sandhya; Jain, Shilpi; Khurana, Raman; Sarkar, Subir; Sharan, Manoj; Abdulsalam, Abdulla; Dutta, Dipanwita; Kailas, Swaminathan; Kumar, Vineet; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Aziz, Tariq; Ganguly, Sanmay; Guchait, Monoranjan; Gurtu, Atul; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mohanty, Gagan Bihari; Parida, Bibhuti; Sudhakar, Katta; Wickramage, Nadeesha; Banerjee, Sudeshna; Dugad, Shashikant; Arfaei, Hessamaddin; Bakhshiansohi, Hamed; Etesami, Seyed Mohsen; Fahim, Ali; Hashemi, Majid; Hesari, Hoda; Jafari, Abideh; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Paktinat Mehdiabadi, Saeid; Safarzadeh, Batool; Zeinali, Maryam; Abbrescia, Marcello; Barbone, Lucia; Calabria, Cesare; Chhibra, Simranjit Singh; Colaleo, Anna; Creanza, Donato; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Maggi, Giorgio; Maggi, Marcello; Marangelli, Bartolomeo; My, Salvatore; Nuzzo, Salvatore; Pacifico, Nicola; Pompili, Alexis; Pugliese, Gabriella; Selvaggi, Giovanna; Silvestris, Lucia; Singh, Gurpreet; Venditti, Rosamaria; Verwilligen, Piet; Zito, Giuseppe; Abbiendi, Giovanni; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Meneghelli, Marco; Montanari, Alessandro; Navarria, Francesco; Odorici, Fabrizio; Perrotta, Andrea; Primavera, Federica; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Tosi, Nicolò; Travaglini, Riccardo; Albergo, Sebastiano; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Frosali, Simone; Gallo, Elisabetta; Gonzi, Sandro; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Benussi, Luigi; Bianco, Stefano; Colafranceschi, Stefano; Fabbri, Franco; Piccolo, Davide; Fabbricatore, Pasquale; Musenich, Riccardo; Tosi, Silvano; Benaglia, Andrea; De Guio, Federico; Di Matteo, Leonardo; Fiorendi, Sara; Gennai, Simone; Ghezzi, Alessio; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Martelli, Arabella; Massironi, Andrea; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Sala, Silvano; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Carrillo Montoya, Camilo Andres; Cavallo, Nicola; De Cosa, Annapaola; Dogangun, Oktay; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lista, Luca; Meola, Sabino; Merola, Mario; Paolucci, Pierluigi; Azzi, Patrizia; Bacchetta, Nicola; Bisello, Dario; Branca, Antonio; Carlin, Roberto; Checchia, Paolo; Dorigo, Tommaso; Gasparini, Fabrizio; Gozzelino, Andrea; Kanishchev, Konstantin; Lacaprara, Stefano; Lazzizzera, Ignazio; Margoni, Martino; Meneguzzo, Anna Teresa; Pazzini, Jacopo; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Triossi, Andrea; Vanini, Sara; Zotto, Pierluigi; Zucchetta, Alberto; Zumerle, Gianni; Gabusi, Michele; Ratti, Sergio P; Riccardi, Cristina; Torre, Paola; Vitulo, Paolo; Biasini, Maurizio; Bilei, Gian Mario; Fanò, Livio; Lariccia, Paolo; Mantovani, Giancarlo; Menichelli, Mauro; Nappi, Aniello; Romeo, Francesco; Saha, Anirban; Santocchia, Attilio; Spiezia, Aniello; Taroni, Silvia; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Broccolo, Giuseppe; Castaldi, Rino; D'Agnolo, Raffaele Tito; Dell'Orso, Roberto; Fiori, Francesco; Foà, Lorenzo; Giassi, Alessandro; Kraan, Aafke; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Rizzi, Andrea; Serban, Alin Titus; Spagnolo, Paolo; Squillacioti, Paola; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; Del Re, Daniele; Diemoz, Marcella; Fanelli, Cristiano; Grassi, Marco; Longo, Egidio; Meridiani, Paolo; Micheli, Francesco; Nourbakhsh, Shervin; Organtini, Giovanni; Paramatti, Riccardo; Rahatlou, Shahram; Sigamani, Michael; Soffi, Livia; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Biino, Cristina; Cartiglia, Nicolo; Casasso, Stefano; Costa, Marco; Demaria, Natale; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Musich, Marco; Obertino, Maria Margherita; Pastrone, Nadia; Pelliccioni, Mario; Potenza, Alberto; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Solano, Ada; Staiano, Amedeo; Belforte, Stefano; Candelise, Vieri; Casarsa, Massimo; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; Marone, Matteo; Montanino, Damiana; Penzo, Aldo; Schizzi, Andrea; Kim, Tae Yeon; Nam, Soon-Kwon; Chang, Sunghyun; Kim, Dong Hee; Kim, Gui Nyun; Kong, Dae Jung; Park, Hyangkyu; Son, Dong-Chul; Son, Taejin; Kim, Jae Yool; Kim, Zero Jaeho; Song, Sanghyeon; Choi, Suyong; Gyun, Dooyeon; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Tae Jeong; Lee, Kyong Sei; Moon, Dong Ho; Park, Sung Keun; Roh, Youn; Choi, Minkyoo; Kim, Ji Hyun; Park, Chawon; Park, Inkyu; Park, Sangnam; Ryu, Geonmo; Choi, Young-Il; Choi, Young Kyu; Goh, Junghwan; Kim, Min Suk; Kwon, Eunhyang; Lee, Byounghoon; Lee, Jongseok; Lee, Sungeun; Seo, Hyunkwan; Yu, Intae; Bilinskas, Mykolas Jurgis; Grigelionis, Ignas; Janulis, Mindaugas; Juodagalvis, Andrius; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-de La Cruz, Ivan; Lopez-Fernandez, Ricardo; Martínez-Ortega, Jorge; Sánchez Hernández, Alberto; Villasenor-Cendejas, Luis Manuel; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Salazar Ibarguen, Humberto Antonio; Casimiro Linares, Edgar; Morelos Pineda, Antonio; Reyes-Santos, Marco A; Krofcheck, David; Bell, Alan James; Butler, Philip H; Doesburg, Robert; Reucroft, Steve; Silverwood, Hamish; Ahmad, Muhammad; Asghar, Muhammad Irfan; Butt, Jamila; Hoorani, Hafeez R; Khalid, Shoaib; Khan, Wajid Ali; Khurshid, Taimoor; Qazi, Shamona; Shah, Mehar Ali; Shoaib, Muhammad; Bialkowska, Helena; Boimska, Bozena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Wrochna, Grzegorz; Zalewski, Piotr; Brona, Grzegorz; Bunkowski, Karol; Cwiok, Mikolaj; Dominik, Wojciech; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Almeida, Nuno; Bargassa, Pedrame; David Tinoco Mendes, Andre; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Seixas, Joao; Varela, Joao; Vischia, Pietro; Bunin, Pavel; Gavrilenko, Mikhail; Golutvin, Igor; Gorbunov, Ilya; Kamenev, Alexey; Karjavin, Vladimir; Kozlov, Guennady; Lanev, Alexander; Malakhov, Alexander; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Savina, Maria; Shmatov, Sergey; Smirnov, Vitaly; Volodko, Anton; Zarubin, Anatoli; Evstyukhin, Sergey; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Vorobyev, Andrey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Kirsanov, Mikhail; Krasnikov, Nikolai; Matveev, Viktor; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Erofeeva, Maria; Gavrilov, Vladimir; Kossov, Mikhail; Lychkovskaya, Natalia; Popov, Vladimir; Safronov, Grigory; Semenov, Sergey; Shreyber, Irina; Stolin, Viatcheslav; Vlasov, Evgueni; Zhokin, Alexander; Belyaev, Andrey; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Gribushin, Andrey; Klyukhin, Vyacheslav; Kodolova, Olga; Lokhtin, Igor; Markina, Anastasia; Obraztsov, Stepan; Perfilov, Maxim; Petrushanko, Sergey; Popov, Andrey; Sarycheva, Ludmila; Savrin, Viktor; Snigirev, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Mesyats, Gennady; Rusakov, Sergey V; Vinogradov, Alexey; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Grishin, Viatcheslav; Kachanov, Vassili; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Djordjevic, Milos; Ekmedzic, Marko; Krpic, Dragomir; Milosevic, Jovan; Aguilar-Benitez, Manuel; Alcaraz Maestre, Juan; Arce, Pedro; Battilana, Carlo; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Domínguez Vázquez, Daniel; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Ferrando, Antonio; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Merino, Gonzalo; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Santaolalla, Javier; Soares, Mara Senghi; Willmott, Carlos; Albajar, Carmen; Codispoti, Giuseppe; de Trocóniz, Jorge F; Brun, Hugues; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Lloret Iglesias, Lara; Piedra Gomez, Jonatan; Brochero Cifuentes, Javier Andres; Cabrillo, Iban Jose; Calderon, Alicia; Chuang, Shan-Huei; Duarte Campderros, Jordi; Felcini, Marta; Fernandez, Marcos; Gomez, Gervasio; Gonzalez Sanchez, Javier; Graziano, Alberto; Jorda, Clara; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Bachtis, Michail; Baillon, Paul; Ball, Austin; Barney, David; Benitez, Jose F; Bernet, Colin; Bianchi, Giovanni; Bloch, Philippe; Bocci, Andrea; Bonato, Alessio; Botta, Cristina; Breuker, Horst; Camporesi, Tiziano; Cerminara, Gianluca; Christiansen, Tim; Coarasa Perez, Jose Antonio; D'Enterria, David; Dabrowski, Anne; De Roeck, Albert; Di Guida, Salvatore; Dobson, Marc; Dupont-Sagorin, Niels; Elliott-Peisert, Anna; Frisch, Benjamin; Funk, Wolfgang; Georgiou, Georgios; Giffels, Manuel; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Girone, Maria; Giunta, Marina; Glege, Frank; Gomez-Reino Garrido, Robert; Govoni, Pietro; Gowdy, Stephen; Guida, Roberto; Gundacker, Stefan; Hammer, Josef; Hansen, Magnus; Harris, Philip; Hartl, Christian; Harvey, John; Hegner, Benedikt; Hinzmann, Andreas; Innocente, Vincenzo; Janot, Patrick; Kaadze, Ketino; Karavakis, Edward; Kousouris, Konstantinos; Lecoq, Paul; Lee, Yen-Jie; Lenzi, Piergiulio; Lourenco, Carlos; Magini, Nicolo; Maki, Tuula; Malberti, Martina; Malgeri, Luca; Mannelli, Marcello; Masetti, Lorenzo; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moser, Roland; Mozer, Matthias Ulrich; Mulders, Martijn; Musella, Pasquale; Nesvold, Erik; Orsini, Luciano; Palencia Cortezon, Enrique; Perez, Emmanuelle; Perrozzi, Luca; Petrilli, Achille; Pfeiffer, Andreas; Pierini, Maurizio; Pimiä, Martti; Piparo, Danilo; Polese, Giovanni; Quertenmont, Loic; Racz, Attila; Reece, William; Rodrigues Antunes, Joao; Rolandi, Gigi; Rovelli, Chiara; Rovere, Marco; Sakulin, Hannes; Santanastasio, Francesco; Schäfer, Christoph; Schwick, Christoph; Segoni, Ilaria; Sekmen, Sezen; Sharma, Archana; Siegrist, Patrice; Silva, Pedro; Simon, Michal; Sphicas, Paraskevas; Spiga, Daniele; Tsirou, Andromachi; Veres, Gabor Istvan; Vlimant, Jean-Roch; Wöhri, Hermine Katharina; Worm, Steven; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Gabathuler, Kurt; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; König, Stefan; Kotlinski, Danek; Langenegger, Urs; Meier, Frank; Renker, Dieter; Rohe, Tilman; Bäni, Lukas; Bortignon, Pierluigi; Buchmann, Marco-Andrea; Casal, Bruno; Chanon, Nicolas; Deisher, Amanda; Dissertori, Günther; Dittmar, Michael; Donegà, Mauro; Dünser, Marc; Eller, Philipp; Eugster, Jürg; Freudenreich, Klaus; Grab, Christoph; Hits, Dmitry; Lecomte, Pierre; Lustermann, Werner; Marini, Andrea Carlo; Martinez Ruiz del Arbol, Pablo; Mohr, Niklas; Moortgat, Filip; Nägeli, Christoph; Nef, Pascal; Nessi-Tedaldi, Francesca; Pandolfi, Francesco; Pape, Luc; Pauss, Felicitas; Peruzzi, Marco; Ronga, Frederic Jean; Rossini, Marco; Sala, Leonardo; Sanchez, Ann - Karin; Starodumov, Andrei; Stieger, Benjamin; Takahashi, Maiko; Tauscher, Ludwig; Thea, Alessandro; Theofilatos, Konstantinos; Treille, Daniel; Urscheler, Christina; Wallny, Rainer; Weber, Hannsjoerg Artur; Wehrli, Lukas; Amsler, Claude; Chiochia, Vincenzo; De Visscher, Simon; Favaro, Carlotta; Ivova Rikova, Mirena; Kilminster, Benjamin; Millan Mejias, Barbara; Otiougova, Polina; Robmann, Peter; Snoek, Hella; Tupputi, Salvatore; Verzetti, Mauro; Chang, Yuan-Hann; Chen, Kuan-Hsin; Ferro, Cristina; Kuo, Chia-Ming; Li, Syue-Wei; Lin, Willis; Lu, Yun-Ju; Singh, Anil; Volpe, Roberta; Yu, Shin-Shan; Bartalini, Paolo; Chang, Paoti; Chang, You-Hao; Chang, Yu-Wei; Chao, Yuan; Chen, Kai-Feng; Dietz, Charles; Grundler, Ulysses; Hou, George Wei-Shu; Hsiung, Yee; Kao, Kai-Yi; Lei, Yeong-Jyi; Lu, Rong-Shyang; Majumder, Devdatta; Petrakou, Eleni; Shi, Xin; Shiu, Jing-Ge; Tzeng, Yeng-Ming; Wan, Xia; Wang, Minzu; Asavapibhop, Burin; Srimanobhas, Norraphat; Adiguzel, Aytul; Bakirci, Mustafa Numan; Cerci, Salim; Dozen, Candan; Dumanoglu, Isa; Eskut, Eda; Girgis, Semiray; Gokbulut, Gul; Gurpinar, Emine; Hos, Ilknur; Kangal, Evrim Ersin; Karaman, Turker; Karapinar, Guler; Kayis Topaksu, Aysel; Onengut, Gulsen; Ozdemir, Kadri; Ozturk, Sertac; Polatoz, Ayse; Sogut, Kenan; Sunar Cerci, Deniz; Tali, Bayram; Topakli, Huseyin; Vergili, Latife Nukhet; Vergili, Mehmet; Akin, Ilina Vasileva; Aliev, Takhmasib; Bilin, Bugra; Bilmis, Selcuk; Deniz, Muhammed; Gamsizkan, Halil; Guler, Ali Murat; Ocalan, Kadir; Ozpineci, Altug; Serin, Meltem; Sever, Ramazan; Surat, Ugur Emrah; Yalvac, Metin; Yildirim, Eda; Zeyrek, Mehmet; Gülmez, Erhan; Isildak, Bora; Kaya, Mithat; Kaya, Ozlem; Ozkorucuklu, Suat; Sonmez, Nasuf; Cankocak, Kerem; Levchuk, Leonid; Brooke, James John; Clement, Emyr; Cussans, David; Flacher, Henning; Frazier, Robert; Goldstein, Joel; Grimes, Mark; Heath, Greg P; Heath, Helen F; Kreczko, Lukasz; Metson, Simon; Newbold, Dave M; Nirunpong, Kachanon; Poll, Anthony; Senkin, Sergey; Smith, Vincent J; Williams, Thomas; Basso, Lorenzo; Bell, Ken W; Belyaev, Alexander; Brew, Christopher; Brown, Robert M; Cockerill, David JA; Coughlan, John A; Harder, Kristian; Harper, Sam; Jackson, James; Kennedy, Bruce W; Olaiya, Emmanuel; Petyt, David; Radburn-Smith, Benjamin Charles; Shepherd-Themistocleous, Claire; Tomalin, Ian R; Womersley, William John; Bainbridge, Robert; Ball, Gordon; Beuselinck, Raymond; Buchmuller, Oliver; Colling, David; Cripps, Nicholas; Cutajar, Michael; Dauncey, Paul; Davies, Gavin; Della Negra, Michel; Ferguson, William; Fulcher, Jonathan; Futyan, David; Gilbert, Andrew; Guneratne Bryer, Arlo; Hall, Geoffrey; Hatherell, Zoe; Hays, Jonathan; Iles, Gregory; Jarvis, Martyn; Karapostoli, Georgia; Lyons, Louis; Magnan, Anne-Marie; Marrouche, Jad; Mathias, Bryn; Nandi, Robin; Nash, Jordan; Nikitenko, Alexander; Pela, Joao; Pesaresi, Mark; Petridis, Konstantinos; Pioppi, Michele; Raymond, David Mark; Rogerson, Samuel; Rose, Andrew; Ryan, Matthew John; Seez, Christopher; Sharp, Peter; Sparrow, Alex; Stoye, Markus; Tapper, Alexander; Vazquez Acosta, Monica; Virdee, Tejinder; Wakefield, Stuart; Wardle, Nicholas; Whyntie, Tom; Chadwick, Matthew; Cole, Joanne; Hobson, Peter R; Khan, Akram; Kyberd, Paul; Leggat, Duncan; Leslie, Dawn; Martin, William; Reid, Ivan; Symonds, Philip; Teodorescu, Liliana; Turner, Mark; Hatakeyama, Kenichi; Liu, Hongxuan; Scarborough, Tara; Charaf, Otman; Henderson, Conor; Rumerio, Paolo; Avetisyan, Aram; Bose, Tulika; Fantasia, Cory; Heister, Arno; St John, Jason; Lawson, Philip; Lazic, Dragoslav; Rohlf, James; Sperka, David; Sulak, Lawrence; Alimena, Juliette; Bhattacharya, Saptaparna; Christopher, Grant; Cutts, David; Demiragli, Zeynep; Ferapontov, Alexey; Garabedian, Alex; Heintz, Ulrich; Jabeen, Shabnam; Kukartsev, Gennadiy; Laird, Edward; Landsberg, Greg; Luk, Michael; Narain, Meenakshi; Nguyen, Duong; Segala, Michael; Sinthuprasith, Tutanon; Speer, Thomas; Breedon, Richard; Breto, Guillermo; Calderon De La Barca Sanchez, Manuel; Chauhan, Sushil; Chertok, Maxwell; Conway, John; Conway, Rylan; Cox, Peter Timothy; Dolen, James; Erbacher, Robin; Gardner, Michael; Houtz, Rachel; Ko, Winston; Kopecky, Alexandra; Lander, Richard; Mall, Orpheus; Miceli, Tia; Pellett, Dave; Ricci-Tam, Francesca; Rutherford, Britney; Searle, Matthew; Smith, John; Squires, Michael; Tripathi, Mani; Vasquez Sierra, Ricardo; Yohay, Rachel; Andreev, Valeri; Cline, David; Cousins, Robert; Duris, Joseph; Erhan, Samim; Everaerts, Pieter; Farrell, Chris; Hauser, Jay; Ignatenko, Mikhail; Jarvis, Chad; Rakness, Gregory; Schlein, Peter; Traczyk, Piotr; Valuev, Vyacheslav; Weber, Matthias; Babb, John; Clare, Robert; Dinardo, Mauro Emanuele; Ellison, John Anthony; Gary, J William; Giordano, Ferdinando; Hanson, Gail; Liu, Hongliang; Long, Owen Rosser; Luthra, Arun; Nguyen, Harold; Paramesvaran, Sudarshan; Sturdy, Jared; Sumowidagdo, Suharyo; Wilken, Rachel; Wimpenny, Stephen; Andrews, Warren; Branson, James G; Cerati, Giuseppe Benedetto; Cittolin, Sergio; Evans, David; Holzner, André; Kelley, Ryan; Lebourgeois, Matthew; Letts, James; Macneill, Ian; Mangano, Boris; Padhi, Sanjay; Palmer, Christopher; Petrucciani, Giovanni; Pieri, Marco; Sani, Matteo; Sharma, Vivek; Simon, Sean; Sudano, Elizabeth; Tadel, Matevz; Tu, Yanjun; Vartak, Adish; Wasserbaech, Steven; Würthwein, Frank; Yagil, Avraham; Yoo, Jaehyeok; Barge, Derek; Bellan, Riccardo; Campagnari, Claudio; D'Alfonso, Mariarosaria; Danielson, Thomas; Flowers, Kristen; Geffert, Paul; Golf, Frank; Incandela, Joe; Justus, Christopher; Kalavase, Puneeth; Kovalskyi, Dmytro; Krutelyov, Vyacheslav; Lowette, Steven; Magaña Villalba, Ricardo; Mccoll, Nickolas; Pavlunin, Viktor; Ribnik, Jacob; Richman, Jeffrey; Rossin, Roberto; Stuart, David; To, Wing; West, Christopher; Apresyan, Artur; Bornheim, Adolf; Chen, Yi; Di Marco, Emanuele; Duarte, Javier; Gataullin, Marat; Ma, Yousi; Mott, Alexander; Newman, Harvey B; Rogan, Christopher; Spiropulu, Maria; Timciuc, Vladlen; Veverka, Jan; Wilkinson, Richard; Xie, Si; Yang, Yong; Zhu, Ren-Yuan; Azzolini, Virginia; Calamba, Aristotle; Carroll, Ryan; Ferguson, Thomas; Iiyama, Yutaro; Jang, Dong Wook; Liu, Yueh-Feng; Paulini, Manfred; Vogel, Helmut; Vorobiev, Igor; Cumalat, John Perry; Drell, Brian Robert; Ford, William T; Gaz, Alessandro; Luiggi Lopez, Eduardo; Smith, James; Stenson, Kevin; Ulmer, Keith; Wagner, Stephen Robert; Alexander, James; Chatterjee, Avishek; Eggert, Nicholas; Gibbons, Lawrence Kent; Heltsley, Brian; Hopkins, Walter; Khukhunaishvili, Aleko; Kreis, Benjamin; Mirman, Nathan; Nicolas Kaufman, Gala; Patterson, Juliet Ritchie; Ryd, Anders; Salvati, Emmanuele; Sun, Werner; Teo, Wee Don; Thom, Julia; Thompson, Joshua; Tucker, Jordan; Vaughan, Jennifer; Weng, Yao; Winstrom, Lucas; Wittich, Peter; Winn, Dave; Abdullin, Salavat; Albrow, Michael; Anderson, Jacob; Bauerdick, Lothar AT; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C; Burkett, Kevin; Butler, Joel Nathan; Chetluru, Vasundhara; Cheung, Harry; Chlebana, Frank; Elvira, Victor Daniel; Fisk, Ian; Freeman, Jim; Gao, Yanyan; Green, Dan; Gutsche, Oliver; Hanlon, Jim; Harris, Robert M; Hirschauer, James; Hooberman, Benjamin; Jindariani, Sergo; Johnson, Marvin; Joshi, Umesh; Klima, Boaz; Kunori, Shuichi; Kwan, Simon; Leonidopoulos, Christos; Linacre, Jacob; Lincoln, Don; Lipton, Ron; Lykken, Joseph; Maeshima, Kaori; Marraffino, John Michael; Maruyama, Sho; Mason, David; McBride, Patricia; Mishra, Kalanand; Mrenna, Stephen; Musienko, Yuri; Newman-Holmes, Catherine; O'Dell, Vivian; Prokofyev, Oleg; Sexton-Kennedy, Elizabeth; Sharma, Seema; Spalding, William J; Spiegel, Leonard; Taylor, Lucas; Tkaczyk, Slawek; Tran, Nhan Viet; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vidal, Richard; Whitmore, Juliana; Wu, Weimin; Yang, Fan; Yun, Jae Chul; Acosta, Darin; Avery, Paul; Bourilkov, Dimitri; Chen, Mingshui; Cheng, Tongguang; Das, Souvik; De Gruttola, Michele; Di Giovanni, Gian Piero; Dobur, Didar; Drozdetskiy, Alexey; Field, Richard D; Fisher, Matthew; Fu, Yu; Furic, Ivan-Kresimir; Gartner, Joseph; Hugon, Justin; Kim, Bockjoo; Konigsberg, Jacobo; Korytov, Andrey; Kropivnitskaya, Anna; Kypreos, Theodore; Low, Jia Fu; Matchev, Konstantin; Milenovic, Predrag; Mitselmakher, Guenakh; Muniz, Lana; Park, Myeonghun; Remington, Ronald; Rinkevicius, Aurelijus; Sellers, Paul; Skhirtladze, Nikoloz; Snowball, Matthew; Yelton, John; Zakaria, Mohammed; Gaultney, Vanessa; Hewamanage, Samantha; Lebolo, Luis Miguel; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Adams, Todd; Askew, Andrew; Bochenek, Joseph; Chen, Jie; Diamond, Brendan; Gleyzer, Sergei V; Haas, Jeff; Hagopian, Sharon; Hagopian, Vasken; Jenkins, Merrill; Johnson, Kurtis F; Prosper, Harrison; Veeraraghavan, Venkatesh; Weinberg, Marc; Baarmand, Marc M; Dorney, Brian; Hohlmann, Marcus; Kalakhety, Himali; Vodopiyanov, Igor; Yumiceva, Francisco; Adams, Mark Raymond; Anghel, Ioana Maria; Apanasevich, Leonard; Bai, Yuting; Bazterra, Victor Eduardo; Betts, Russell Richard; Bucinskaite, Inga; Callner, Jeremy; Cavanaugh, Richard; Evdokimov, Olga; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Khalatyan, Samvel; Lacroix, Florent; O'Brien, Christine; Silkworth, Christopher; Strom, Derek; Turner, Paul; Varelas, Nikos; Akgun, Ugur; Albayrak, Elif Asli; Bilki, Burak; Clarida, Warren; Duru, Firdevs; Griffiths, Scott; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Newsom, Charles Ray; Norbeck, Edwin; Onel, Yasar; Ozok, Ferhat; Sen, Sercan; Tan, Ping; Tiras, Emrah; Wetzel, James; Yetkin, Taylan; Yi, Kai; Barnett, Bruce Arnold; Blumenfeld, Barry; Bolognesi, Sara; Fehling, David; Giurgiu, Gavril; Gritsan, Andrei; Guo, Zijin; Hu, Guofan; Maksimovic, Petar; Swartz, Morris; Whitbeck, Andrew; Baringer, Philip; Bean, Alice; Benelli, Gabriele; Kenny Iii, Raymond Patrick; Murray, Michael; Noonan, Daniel; Sanders, Stephen; Stringer, Robert; Tinti, Gemma; Wood, Jeffrey Scott; Barfuss, Anne-Fleur; Bolton, Tim; Chakaberia, Irakli; Ivanov, Andrew; Khalil, Sadia; Makouski, Mikhail; Maravin, Yurii; Shrestha, Shruti; Svintradze, Irakli; Gronberg, Jeffrey; Lange, David; Rebassoo, Finn; Wright, Douglas; Baden, Drew; Calvert, Brian; Eno, Sarah Catherine; Gomez, Jaime; Hadley, Nicholas John; Kellogg, Richard G; Kirn, Malina; Kolberg, Ted; Lu, Ying; Marionneau, Matthieu; Mignerey, Alice; Pedro, Kevin; Skuja, Andris; Temple, Jeffrey; Tonjes, Marguerite; Tonwar, Suresh C; Apyan, Aram; Bauer, Gerry; Bendavid, Joshua; Busza, Wit; Butz, Erik; Cali, Ivan Amos; Chan, Matthew; Dutta, Valentina; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Kim, Yongsun; Klute, Markus; Krajczar, Krisztian; Levin, Andrew; Luckey, Paul David; Ma, Teng; Nahn, Steve; Paus, Christoph; Ralph, Duncan; Roland, Christof; Roland, Gunther; Rudolph, Matthew; Stephans, George; Stöckli, Fabian; Sumorok, Konstanty; Sung, Kevin; Velicanu, Dragos; Wenger, Edward Allen; Wolf, Roger; Wyslouch, Bolek; Yang, Mingming; Yilmaz, Yetkin; Yoon, Sungho; Zanetti, Marco; Zhukova, Victoria; Cooper, Seth; Dahmes, Bryan; De Benedetti, Abraham; Franzoni, Giovanni; Gude, Alexander; Kao, Shih-Chuan; Klapoetke, Kevin; Kubota, Yuichi; Mans, Jeremy; Pastika, Nathaniel; Rusack, Roger; Sasseville, Michael; Singovsky, Alexander; Tambe, Norbert; Turkewitz, Jared; Cremaldi, Lucien Marcus; Kroeger, Rob; Perera, Lalith; Rahmat, Rahmat; Sanders, David A; Avdeeva, Ekaterina; Bloom, Kenneth; Bose, Suvadeep; Claes, Daniel R; Dominguez, Aaron; Eads, Michael; Keller, Jason; Kravchenko, Ilya; Lazo-Flores, Jose; Malik, Sudhir; Snow, Gregory R; Godshalk, Andrew; Iashvili, Ia; Jain, Supriya; Kharchilava, Avto; Kumar, Ashish; Rappoccio, Salvatore; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Chasco, Matthew; Haley, Joseph; Nash, David; Orimoto, Toyoko; Trocino, Daniele; Wood, Darien; Zhang, Jinzhong; Anastassov, Anton; Hahn, Kristan Allan; Kubik, Andrew; Lusito, Letizia; Mucia, Nicholas; Odell, Nathaniel; Ofierzynski, Radoslaw Adrian; Pollack, Brian; Pozdnyakov, Andrey; Schmitt, Michael; Stoynev, Stoyan; Velasco, Mayda; Won, Steven; Antonelli, Louis; Berry, Douglas; Brinkerhoff, Andrew; Chan, Kwok Ming; Hildreth, Michael; Jessop, Colin; Karmgard, Daniel John; Kolb, Jeff; Lannon, Kevin; Luo, Wuming; Lynch, Sean; Marinelli, Nancy; Morse, David Michael; Pearson, Tessa; Planer, Michael; Ruchti, Randy; Slaunwhite, Jason; Valls, Nil; Wayne, Mitchell; Wolf, Matthias; Bylsma, Ben; Durkin, Lloyd Stanley; Hill, Christopher; Hughes, Richard; Kotov, Khristian; Ling, Ta-Yung; Puigh, Darren; Rodenburg, Marissa; Vuosalo, Carl; Williams, Grayson; Winer, Brian L; Berry, Edmund; Elmer, Peter; Halyo, Valerie; Hebda, Philip; Hegeman, Jeroen; Hunt, Adam; Jindal, Pratima; Koay, Sue Ann; Lopes Pegna, David; Lujan, Paul; Marlow, Daniel; Medvedeva, Tatiana; Mooney, Michael; Olsen, James; Piroué, Pierre; Quan, Xiaohang; Raval, Amita; Saka, Halil; Stickland, David; Tully, Christopher; Werner, Jeremy Scott; Zuranski, Andrzej; Brownson, Eric; Lopez, Angel; Mendez, Hector; Ramirez Vargas, Juan Eduardo; Alagoz, Enver; Barnes, Virgil E; Benedetti, Daniele; Bolla, Gino; Bortoletto, Daniela; De Mattia, Marco; Everett, Adam; Hu, Zhen; Jones, Matthew; Koybasi, Ozhan; Kress, Matthew; Laasanen, Alvin T; Leonardo, Nuno; Maroussov, Vassili; Merkel, Petra; Miller, David Harry; Neumeister, Norbert; Shipsey, Ian; Silvers, David; Svyatkovskiy, Alexey; Vidal Marono, Miguel; Yoo, Hwi Dong; Zablocki, Jakub; Zheng, Yu; Guragain, Samir; Parashar, Neeti; Adair, Antony; Akgun, Bora; Boulahouache, Chaouki; Ecklund, Karl Matthew; Geurts, Frank JM; Li, Wei; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Zabel, James; Betchart, Burton; Bodek, Arie; Chung, Yeon Sei; Covarelli, Roberto; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Ferbel, Thomas; Garcia-Bellido, Aran; Goldenzweig, Pablo; Han, Jiyeon; Harel, Amnon; Miner, Daniel Carl; Vishnevskiy, Dmitry; Zielinski, Marek; Bhatti, Anwar; Ciesielski, Robert; Demortier, Luc; Goulianos, Konstantin; Lungu, Gheorghe; Malik, Sarah; Mesropian, Christina; Arora, Sanjay; Barker, Anthony; Chou, John Paul; Contreras-Campana, Christian; Contreras-Campana, Emmanuel; Duggan, Daniel; Ferencek, Dinko; Gershtein, Yuri; Gray, Richard; Halkiadakis, Eva; Hidas, Dean; Lath, Amitabh; Panwalkar, Shruti; Park, Michael; Patel, Rishi; Rekovic, Vladimir; Robles, Jorge; Rose, Keith; Salur, Sevil; Schnetzer, Steve; Seitz, Claudia; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Walker, Matthew; Cerizza, Giordano; Hollingsworth, Matthew; Spanier, Stefan; Yang, Zong-Chang; York, Andrew; Eusebi, Ricardo; Flanagan, Will; Gilmore, Jason; Kamon, Teruki; Khotilovich, Vadim; Montalvo, Roy; Osipenkov, Ilya; Pakhotin, Yuriy; Perloff, Alexx; Roe, Jeffrey; Safonov, Alexei; Sakuma, Tai; Sengupta, Sinjini; Suarez, Indara; Tatarinov, Aysen; Toback, David; Akchurin, Nural; Damgov, Jordan; Dragoiu, Cosmin; Dudero, Phillip Russell; Jeong, Chiyoung; Kovitanggoon, Kittikul; Lee, Sung Won; Libeiro, Terence; Volobouev, Igor; Appelt, Eric; Delannoy, Andrés G; Florez, Carlos; Greene, Senta; Gurrola, Alfredo; Johns, Willard; Kurt, Pelin; Maguire, Charles; Melo, Andrew; Sharma, Monika; Sheldon, Paul; Snook, Benjamin; Tuo, Shengquan; Velkovska, Julia; Arenton, Michael Wayne; Balazs, Michael; Boutle, Sarah; Cox, Bradley; Francis, Brian; Goodell, Joseph; Hirosky, Robert; Ledovskoy, Alexander; Lin, Chuanzhe; Neu, Christopher; Wood, John; Gollapinni, Sowjanya; Harr, Robert; Karchin, Paul Edmund; Kottachchi Kankanamge Don, Chamath; Lamichhane, Pramod; Sakharov, Alexandre; Anderson, Michael; Belknap, Donald; Borrello, Laura; Carlsmith, Duncan; Cepeda, Maria; Dasu, Sridhara; Friis, Evan; Gray, Lindsey; Grogg, Kira Suzanne; Grothe, Monika; Hall-Wilton, Richard; Herndon, Matthew; Hervé, Alain; Klabbers, Pamela; Klukas, Jeffrey; Lanaro, Armando; Lazaridis, Christos; Loveless, Richard; Mohapatra, Ajit; Ojalvo, Isabel; Palmonari, Francesco; Pierro, Giuseppe Antonio; Ross, Ian; Savin, Alexander; Smith, Wesley H; Swanson, Joshua

    2013-01-01

    The results of searches for supersymmetry by the CMS experiment are interpreted in the framework of simplified models. The results are based on data corresponding to an integrated luminosity of 4.73 to 4.98 inverse femtobarns. The data were collected at the LHC in proton-proton collisions at a center-of-mass energy of 7 TeV. This paper describes the method of interpretation and provides upper limits on the product of the production cross section and branching fraction as a function of new particle masses for a number of simplified models. These limits and the corresponding experimental acceptance calculations can be used to constrain other theoretical models and to compare different supersymmetry-inspired analyses.

  4. Implications of Higgs Searches on the Four Generation Standard Model

    CERN Document Server

    Kuflik, Eric; Volansky, Tomer

    2013-01-01

    The Standard Model supplemented with a fourth generation implies significant deviations in the Higgs couplings to gluons and photons compared to the SM prediction. As a consequence, large departure in several Higgs production and decay channels are expected. Recent Higgs search results presented by ATLAS, CMS and CDF hint on the existence of a Higgs boson with a mass around 125 GeV. Using these results and assuming such a light Higgs boson, we derive an exclusion limit on the four generation Standard Model. In particular, for m_H = 125 GeV, a four generation Standard Model is excluded at 99.6% confidence level, while for m_H >= 123 GeV, an exclusion limit above 95% confidence level is found.

  5. Language bootstrapping: learning word meanings from perception-action association.

    Science.gov (United States)

    Salvi, Giampiero; Montesano, Luis; Bernardino, Alexandre; Santos-Victor, José

    2012-06-01

    We address the problem of bootstrapping language acquisition for an artificial system similarly to what is observed in experiments with human infants. Our method works by associating meanings to words in manipulation tasks, as a robot interacts with objects and listens to verbal descriptions of the interactions. The model is based on an affordance network, i.e., a mapping between robot actions, robot perceptions, and the perceived effects of these actions upon objects. We extend the affordance model to incorporate spoken words, which allows us to ground the verbal symbols to the execution of actions and the perception of the environment. The model takes verbal descriptions of a task as the input and uses temporal co-occurrence to create links between speech utterances and the involved objects, actions, and effects. We show that the robot is able form useful word-to-meaning associations, even without considering grammatical structure in the learning process and in the presence of recognition errors. These word-to-meaning associations are embedded in the robot's own understanding of its actions. Thus, they can be directly used to instruct the robot to perform tasks and also allow to incorporate context in the speech recognition task. We believe that the encouraging results with our approach may afford robots with a capacity to acquire language descriptors in their operation's environment as well as to shed some light as to how this challenging process develops with human infants.

  6. Simulation of bootstrap current in 2D and 3D ideal magnetic fields in tokamaks

    Science.gov (United States)

    Raghunathan, M.; Graves, J. P.; Cooper, W. A.; Pedro, M.; Sauter, O.

    2016-09-01

    We aim to simulate the bootstrap current for a MAST-like spherical tokamak using two approaches for magnetic equilibria including externally caused 3D effects such as resonant magnetic perturbations (RMPs), the effect of toroidal ripple, and intrinsic 3D effects such as non-resonant internal kink modes. The first approach relies on known neoclassical coefficients in ideal MHD equilibria, using the Sauter (Sauter et al 1999 Phys. Plasmas 6 2834) expression valid for all collisionalities in axisymmetry, and the second approach being the quasi-analytic Shaing–Callen (Shaing and Callen 1983 Phys. Fluids 26 3315) model in the collisionless regime for 3D. Using the ideal free-boundary magnetohydrodynamic code VMEC, we compute the flux-surface averaged bootstrap current density, with the Sauter and Shaing–Callen expressions for 2D and 3D ideal MHD equilibria including an edge pressure barrier with the application of resonant magnetic perturbations, and equilibria possessing a saturated non-resonant 1/1 internal kink mode with a weak internal pressure barrier. We compare the applicability of the self-consistent iterative model on the 3D applications and discuss the limitations and advantages of each bootstrap current model for each type of equilibrium.

  7. Modeling of pheromone communication system of forest Lepidopterous insects. II. Model of female searching by male

    Directory of Open Access Journals (Sweden)

    A. V. Kovalev

    2015-06-01

    Full Text Available We propose an agent­based simulation model search. This model allows us to evaluate the effectiveness of different males­females pheromone search strategies for Lepidoptera. In the model, we consider the simplest case of the search, when the pheromone has only one chemical component. It is assumed that the insects are able to detect the pheromone molecules and the sensory cells generate action potentials in contact with the pheromone for some time. Thereafter pheromone molecule is inactivated. This behavior can be regarded as a memory of individual. Proportion of individuals who have reached the source is selected as an integral indicator of the search efficiency. To evaluate the effectiveness, numeric experiments were performed in different conditions: random walk, search algorithm without memory, and algorithm with memory and return mechanism. The resulting effectiveness of source localization by insects for flight in turbulent flows is ~ 70 %, which corresponds to experiments with live specimens in literature. In this case, proposed pheromone search algorithm is quite simple, which makes it biologically correct. Conducted modeling calculations can be the starting point for planning of field observations and pest monitoring systems using pheromone traps.

  8. Efficient Approach for Semantic Web Searching Using Markov Model

    OpenAIRE

    Pradeep Salve; Rajesh Chakrawarti

    2012-01-01

    The semantic search usually the web pages for the required information and filter the pages from semantic web searching unnecessary pages by using advanced algorithms. Web pages are vulnerable in answering intelligent semantic search from the user due to the confidence of their consequences on information obtainable in web pages. To get the trusted results semantic web search engines require searching for pages that maintain such information at some place including domain knowledge. The layer...

  9. Multiple Retrieval Models and Regression Models for Prior Art Search

    CERN Document Server

    Lopez, Patrice

    2009-01-01

    This paper presents the system called PATATRAS (PATent and Article Tracking, Retrieval and AnalysiS) realized for the IP track of CLEF 2009. Our approach presents three main characteristics: 1. The usage of multiple retrieval models (KL, Okapi) and term index definitions (lemma, phrase, concept) for the three languages considered in the present track (English, French, German) producing ten different sets of ranked results. 2. The merging of the different results based on multiple regression models using an additional validation set created from the patent collection. 3. The exploitation of patent metadata and of the citation structures for creating restricted initial working sets of patents and for producing a final re-ranking regression model. As we exploit specific metadata of the patent documents and the citation relations only at the creation of initial working sets and during the final post ranking step, our architecture remains generic and easy to extend.

  10. A Bootstrap Approach to Martian Manufacturing

    Science.gov (United States)

    Dorais, Gregory A.

    2004-01-01

    In-Situ Resource Utilization (ISRU) is an essential element of any affordable strategy for a sustained human presence on Mars. Ideally, Martian habitats would be extremely massive to allow plenty of room to comfortably live and work, as well as to protect the occupants from the environment. Moreover, transportation and power generation systems would also require significant mass if affordable. For our approach to ISRU, we use the industrialization of the U.S. as a metaphor. The 19th century started with small blacksmith shops and ended with massive steel mills primarily accomplished by blacksmiths increasing their production capacity and product size to create larger shops, which produced small mills, which produced the large steel mills that industrialized the country. Most of the mass of a steel mill is comprised of steel in simple shapes, which are produced and repaired with few pieces of equipment also mostly made of steel in basic shapes. Due to this simplicity, we expect that the 19th century manufacturing growth can be repeated on Mars in the 21st century using robots as the primary labor force. We suggest a "bootstrap" approach to manufacturing on Mars that uses a "seed" manufacturing system that uses regolith to create major structural components and spare parts. The regolith would be melted, foamed, and sintered as needed to fabricate parts using casting and solid freeform fabrication techniques. Complex components, such as electronics, would be brought from Earth and integrated as needed. These parts would be assembled to create additional manufacturing systems, which can be both more capable and higher capacity. These subsequent manufacturing systems could refine vast amounts of raw materials to create large components, as well as assemble equipment, habitats, pressure vessels, cranes, pipelines, railways, trains, power generation stations, and other facilities needed to economically maintain a sustained human presence on Mars.

  11. Parameter Estimation of Photovoltaic Models via Cuckoo Search

    Directory of Open Access Journals (Sweden)

    Jieming Ma

    2013-01-01

    Full Text Available Since conventional methods are incapable of estimating the parameters of Photovoltaic (PV models with high accuracy, bioinspired algorithms have attracted significant attention in the last decade. Cuckoo Search (CS is invented based on the inspiration of brood parasitic behavior of some cuckoo species in combination with the Lévy flight behavior. In this paper, a CS-based parameter estimation method is proposed to extract the parameters of single-diode models for commercial PV generators. Simulation results and experimental data show that the CS algorithm is capable of obtaining all the parameters with extremely high accuracy, depicted by a low Root-Mean-Squared-Error (RMSE value. The proposed method outperforms other algorithms applied in this study.

  12. Direct search for the Standard Model Higgs boson

    Science.gov (United States)

    Janot, Patrick; Kado, Marumi

    2002-11-01

    For twelve years, LEP revolutionized the knowledge of electroweak symmetry breaking within the standard model, and the direct discovery of the Higgs boson would have been the crowning achievement. Searches at the Z resonance and above the W +W - threshold allowed an unambiguous lower limit on the mass of the standard model Higgs boson to set be at 114.1 GeV· c-2. After years of efforts to push the LEP performance far beyond the design limits, hints of what could be the first signs of the existence of a 115 GeV· c-2 Higgs boson appeared in June 2000, were confirmed in September, and were then confirmed again in November. An additional six-month period of LEP operation was enough to provide a definite answer, with an opportunity to make a fundamental discovery of prime importance. To cite this article: P. Janot, M. Kado, C. R. Physique 3 (2002) 1193-1202.

  13. Direct search for the standard model Higgs boson

    CERN Document Server

    Janot, Patrick

    2002-01-01

    For twelve years, LEP revolutionized the knowledge of electroweak symmetry breaking within the standard model, and the direct discovery of the Higgs boson would have been the crowning achievement. Searches at the Z resonance and above the W/sup +/W/sup -/ threshold allowed an unambiguous lower limit on the mass of the standard model Higgs boson to set be at 114.1 GeV.c/sup -2/. After years of efforts to push the LEP performance far beyond the design limits, hints of what could be the first signs of the existence of a 115 GeV-c/sup -2/ Higgs boson appeared in June 2000, were confirmed in September, and were then confirmed again in November. An additional six-month period of LEP operation was enough to provide a definite answer, with an opportunity to make a fundamental discovery of prime importance. (37 refs).

  14. Model-Independent and Quasi-Model-Independent Search for New Physics at CDF

    CERN Document Server

    Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; Alvarez-Gonzalez, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P H; Bedeschi, F; Bednar, P; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bölla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, Yu A; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrerar, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carrillol, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cerri, A; Cerritop, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenarr, C; Cuevaso, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; De Barbaro, P; De Cecco, S; Deisher, A; De Lentdeckerd, G; Dell'Orso, Mauro; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernández, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; García, J E; Garfinkel, A F; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokarisa, N; Giordani, M; Giromini, P; Giunta, M; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldsteinc, J; Golossanov, A; Gómez, G; Gómez-Ceballos, G; Goncharov, M; Gonzlez, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraesda Costa, J; Gunay-Unalan, Z; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hillc, C S; Hirschbuehl, D; Höcker, A; Hou, S; Houlden, M; Hsu, S C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Koay, S A; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Le Compte, T; Lee, J; Lee, J; Lee, Y J; Leeq, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lu, R S; Lucchesi, D; Lueck, J; Luci, C; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Mäki, T; Maksimovic, P; Malde, S; Malik, S; Manousakisa, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, M; Martinj, V; Martinez-Ballarin, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNultyi, R; Mehta, A; Mehtälä, P; Menzemerk, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moed, S; Moggi, N; Moon, C S; Moore, R; Morello, M; Movilla-Fernández, P A; Mrenna, S; Mulmenstdt, J; Mukherjee, A; Müller, T; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Österberg, K; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S

    2007-01-01

    Data collected in Run II of the Fermilab Tevatron are searched for indications of new electroweak scale physics. Rather than focusing on particular new physics scenarios, CDF data are analyzed for discrepancies with respect to the standard model prediction. A model-independent approach (Vista) considers the gross features of the data, and is sensitive to new large cross section physics. A quasi-model-independent approach (Sleuth) searches for a significant excess of events with large summed transverse momentum, and is particularly sensitive to new electroweak scale physics that appears predominantly in one final state. This global search for new physics in over three hundred exclusive final states in 927 pb^-1 of ppbar collisions at sqrt(s)=1.96 TeV reveals no such significant indication of physics beyond the standard model.

  15. Antecedents and Outcomes of Search Engines Loyalty: Designing a model of Iranian Users Loyalty

    Directory of Open Access Journals (Sweden)

    Alireza Hadadian

    2013-09-01

    Full Text Available This paper aims to design proposed model for search engine designers to promote loyalty levels of search engine users. This is a descriptive survey study. The statistical population of the research is composed of Ferdowsi University students. The sample size estimated to be 347. Data gathering instrument was a self administered questionnaire and structural equation modeling (SEM is used for the data analysis. Findings indicate that user communication affects user satisfaction significantly and negatively. Also in research final model search engine image, search engine perceived quality and search engine perceived value affects user satisfaction. Moreover, search engine perceived value affects user loyalty and verbal advertising directly. Also user satisfaction affects user loyalty directly. Finally user loyalty leads into high expected switching costs, search engine revisit and verbal advertising for search engines.

  16. Measuring Efficiency of Tunisian Schools in the Presence of Quasi-Fixed Inputs: A Bootstrap Data Envelopment Analysis Approach

    Science.gov (United States)

    Essid, Hedi; Ouellette, Pierre; Vigeant, Stephane

    2010-01-01

    The objective of this paper is to measure the efficiency of high schools in Tunisia. We use a statistical data envelopment analysis (DEA)-bootstrap approach with quasi-fixed inputs to estimate the precision of our measure. To do so, we developed a statistical model serving as the foundation of the data generation process (DGP). The DGP is…

  17. Specification Search for Identifying the Correct Mean Trajectory in Polynomial Latent Growth Models

    Science.gov (United States)

    Kim, Minjung; Kwok, Oi-Man; Yoon, Myeongsun; Willson, Victor; Lai, Mark H. C.

    2016-01-01

    This study investigated the optimal strategy for model specification search under the latent growth modeling (LGM) framework, specifically on searching for the correct polynomial mean or average growth model when there is no a priori hypothesized model in the absence of theory. In this simulation study, the effectiveness of different starting…

  18. Semantic Web Search based on Ontology Modeling using Protege Reasoner

    OpenAIRE

    Shekhar, Monica; K, Saravanaguru RA.

    2013-01-01

    The Semantic Web works on the existing Web which presents the meaning of information as well-defined vocabularies understood by the people. Semantic Search, at the same time, works on improving the accuracy if a search by understanding the intent of the search and providing contextually relevant results. This paper describes a semantic approach toward web search through a PHP application. The goal was to parse through a user's browsing history and return semantically relevant web pages for th...

  19. N=4 Superconformal Bootstrap of the K3 CFT

    CERN Document Server

    Lin, Ying-Hsuan; Simmons-Duffin, David; Wang, Yifan; Yin, Xi

    2015-01-01

    We study two-dimensional (4,4) superconformal field theories of central charge c=6, corresponding to nonlinear sigma models on K3 surfaces, using the superconformal bootstrap. This is made possible through a surprising relation between the BPS N=4 superconformal blocks with c=6 and bosonic Virasoro conformal blocks with c=28, and an exact result on the moduli dependence of a certain integrated BPS 4-point function. Nontrivial bounds on the non-BPS spectrum in the K3 CFT are obtained as functions of the CFT moduli, that interpolate between the free orbifold points and singular CFT points. We observe directly from the CFT perspective the signature of a continuous spectrum above a gap at the singular moduli, and find numerically an upper bound on this gap that is saturated by the $A_1$ N=4 cigar CFT. We also derive an analytic upper bound on the first nonzero eigenvalue of the scalar Laplacian on K3 in the large volume regime, that depends on the K3 moduli data. As two byproducts, we find an exact equivalence be...

  20. N=4 Superconformal Bootstrap of the K3 CFT

    CERN Document Server

    CERN. Geneva

    2015-01-01

    We study two-dimensional (4,4) superconformal field theories of central charge c=6, corresponding to nonlinear σ models on K3 surfaces, using the superconformal bootstrap. This is made possible through a surprising relation between the BPS N=4 superconformal blocks with c=6 and bosonic Virasoro conformal blocks with c=28, and an exact result on the moduli dependence of a certain integrated BPS 4-point function. Nontrivial bounds on the non-BPS spectrum in the K3 CFT are obtained as functions of the CFT moduli, that interpolate between the free orbifold points and singular CFT points. We observe directly from the CFT perspective the signature of a continuous spectrum above a gap at the singular moduli, and find numerically an upper bound on this gap that is saturated by the A1 N=4 cigar CFT. We also derive an analytic upper bound on the first nonzero eigenvalue of the scalar Laplacian on K3 in the large volume regime, that depends on the K3 moduli data. As two byproducts, we find an exact equivalence...

  1. Locality, bulk equations of motion and the conformal bootstrap

    CERN Document Server

    Kabat, Daniel

    2016-01-01

    We develop an approach to construct local bulk operators in a CFT to order 1/N^2. Since 4-point functions are not fixed by conformal invariance we use the OPE to categorize possible forms for a bulk operator. Using previous results on 3-point functions we construct a local bulk operator in each OPE channel. We then impose the condition that the bulk operators constructed in different channels agree, and hence give rise to a well-defined bulk operator. We refer to this condition as the "bulk bootstrap." We argue and explicitly show in some examples that the bulk bootstrap leads to some of the same results as the regular conformal bootstrap. In fact the bulk bootstrap provides an easier way to determine some CFT data, since it does not require knowing the form of the conformal blocks. This analysis clarifies previous results on the relation between bulk locality and the bootstrap for theories with a 1/N expansion, and it identifies a simple and direct way in which OPE coefficients and anomalous dimensions deter...

  2. An inferential study of the phenotype for the chromosome 15q24 microdeletion syndrome: a bootstrap analysis

    Science.gov (United States)

    Ramírez-Prado, Dolores; Cortés, Ernesto; Aguilar-Segura, María Soledad; Gil-Guillén, Vicente Francisco

    2016-01-01

    In January 2012, a review of the cases of chromosome 15q24 microdeletion syndrome was published. However, this study did not include inferential statistics. The aims of the present study were to update the literature search and calculate confidence intervals for the prevalence of each phenotype using bootstrap methodology. Published case reports of patients with the syndrome that included detailed information about breakpoints and phenotype were sought and 36 were included. Deletions in megabase (Mb) pairs were determined to calculate the size of the interstitial deletion of the phenotypes studied in 2012. To determine confidence intervals for the prevalence of the phenotype and the interstitial loss, we used bootstrap methodology. Using the bootstrap percentiles method, we found wide variability in the prevalence of the different phenotypes (3–100%). The mean interstitial deletion size was 2.72 Mb (95% CI [2.35–3.10 Mb]). In comparison with our work, which expanded the literature search by 45 months, there were differences in the prevalence of 17% of the phenotypes, indicating that more studies are needed to analyze this rare disease. PMID:26925314

  3. FURTHER EVALUATION OF BOOTSTRAP RESAMPLING AS A TOOL FOR RADIO-INTERFEROMETRIC IMAGING FIDELITY ASSESSMENT

    International Nuclear Information System (INIS)

    We report on a broader evaluation of statistical bootstrap resampling methods as a tool for pixel-level calibration and imaging fidelity assessment in radio interferometry. Pixel-level imaging fidelity assessment is a challenging problem, important for the value it holds in robust scientific interpretation of interferometric images, enhancement of automated pipeline reduction systems needed to broaden the user community for these instruments, and understanding leading-edge direction-dependent calibration and imaging challenges for future telescopes such as the Square Kilometre Array. This new computational approach is now possible because of advances in statistical resampling for data with long-range dependence and the available performance of contemporary high-performance computing resources. We expand our earlier numerical evaluation to span a broader domain subset in simulated image fidelity and source brightness distribution morphologies. As before, we evaluate the statistical performance of the bootstrap resampling methods against direct Monte Carlo simulation. We find that both model-based and subsample bootstrap methods continue to show significant promise for the challenging problem of interferometric imaging fidelity assessment when evaluated over the broader domain subset. We report on their measured statistical performance and guidelines for their use and application in practice. We also examine the performance of the underlying polarization self-calibration algorithm used in this study over a range of parallactic angle coverage.

  4. Thermal Image Sensing Model for Robotic Planning and Search.

    Science.gov (United States)

    Castro Jiménez, Lídice E; Martínez-García, Edgar A

    2016-01-01

    This work presents a search planning system for a rolling robot to find a source of infra-red (IR) radiation at an unknown location. Heat emissions are observed by a low-cost home-made IR passive visual sensor. The sensor capability for detection of radiation spectra was experimentally characterized. The sensor data were modeled by an exponential model to estimate the distance as a function of the IR image's intensity, and, a polynomial model to estimate temperature as a function of IR intensities. Both theoretical models are combined to deduce a subtle nonlinear exact solution via distance-temperature. A planning system obtains feed back from the IR camera (position, intensity, and temperature) to lead the robot to find the heat source. The planner is a system of nonlinear equations recursively solved by a Newton-based approach to estimate the IR-source in global coordinates. The planning system assists an autonomous navigation control in order to reach the goal and avoid collisions. Trigonometric partial differential equations were established to control the robot's course towards the heat emission. A sine function produces attractive accelerations toward the IR source. A cosine function produces repulsive accelerations against the obstacles observed by an RGB-D sensor. Simulations and real experiments of complex indoor are presented to illustrate the convenience and efficacy of the proposed approach. PMID:27509510

  5. Thermal Image Sensing Model for Robotic Planning and Search

    Science.gov (United States)

    Castro Jiménez, Lídice E.; Martínez-García, Edgar A.

    2016-01-01

    This work presents a search planning system for a rolling robot to find a source of infra-red (IR) radiation at an unknown location. Heat emissions are observed by a low-cost home-made IR passive visual sensor. The sensor capability for detection of radiation spectra was experimentally characterized. The sensor data were modeled by an exponential model to estimate the distance as a function of the IR image’s intensity, and, a polynomial model to estimate temperature as a function of IR intensities. Both theoretical models are combined to deduce a subtle nonlinear exact solution via distance-temperature. A planning system obtains feed back from the IR camera (position, intensity, and temperature) to lead the robot to find the heat source. The planner is a system of nonlinear equations recursively solved by a Newton-based approach to estimate the IR-source in global coordinates. The planning system assists an autonomous navigation control in order to reach the goal and avoid collisions. Trigonometric partial differential equations were established to control the robot’s course towards the heat emission. A sine function produces attractive accelerations toward the IR source. A cosine function produces repulsive accelerations against the obstacles observed by an RGB-D sensor. Simulations and real experiments of complex indoor are presented to illustrate the convenience and efficacy of the proposed approach. PMID:27509510

  6. A Strategy Tackling Local Minimum of Direct Search Method in Modeling a Hydraulic Actuator

    Institute of Scientific and Technical Information of China (English)

    刘云山; 陈晓辉

    2013-01-01

    A strategy for attacking the local minimum problem of direct search method is developed for modeling a hydraulic actuator. The Nelder-Mead direct search method is combined with Ordinary Least Squares which can used to optimize the parameters which the model function is in linear with. The model fitting results show that this strategy can reach a solution more close to the global minimum than the Nelder-Mead direct search method used alone.

  7. Design and Implementation of a Bootstrap Trust Chain

    Institute of Scientific and Technical Information of China (English)

    YU Fajiang; ZHANG Huanguo

    2006-01-01

    The chain of trust in bootstrap process is the basis of whole system trust in the trusted computing group (TCG) definition. This paper presents a design and implementation of a bootstrap trust chain in PC based on the Windows and today' commodity hardware, merely depends on availability of an embedded security module (ESM). ESM and security enhanced BIOS is the root of trust, PMBR (Pre-MBR) checks the integrity of boot data and Windows kernel, which is a checking agent stored in ESM. In the end, the paper analyzed the mathematic expression of the chain of trust and the runtime performance compared with the common booting process. The trust chain bootstrap greatly strengthens the security of personal computer system, and affects the runtime performance with only adding about 12% booting time.

  8. A Bootstrap Algebraic Multilevel method for Markov Chains

    CERN Document Server

    Bolten, M; Brannick, J; Frommer, A; Kahl, K; Livshits, I

    2010-01-01

    This work concerns the development of an Algebraic Multilevel method for computing stationary vectors of Markov chains. We present an efficient Bootstrap Algebraic Multilevel method for this task. In our proposed approach, we employ a multilevel eigensolver, with interpolation built using ideas based on compatible relaxation, algebraic distances, and least squares fitting of test vectors. Our adaptive variational strategy for computation of the state vector of a given Markov chain is then a combination of this multilevel eigensolver and associated multilevel preconditioned GMRES iterations. We show that the Bootstrap AMG eigensolver by itself can efficiently compute accurate approximations to the state vector. An additional benefit of the Bootstrap approach is that it yields an accurate interpolation operator for many other eigenmodes. This in turn allows for the use of the resulting AMG hierarchy to accelerate the MLE steps using standard multigrid correction steps. The proposed approach is applied to a rang...

  9. Addressing the P2P Bootstrap Problem for Small Networks

    CERN Document Server

    Wolinsky, David Isaac; Boykin, P Oscar; Figueiredo, Renato

    2010-01-01

    P2P overlays provide a framework for building distributed applications consisting of few to many resources with features including self-configuration, scalability, and resilience to node failures. Such systems have been successfully adopted in large-scale services for content delivery networks, file sharing, and data storage. In small-scale systems, they can be useful to address privacy concerns and for network applications that lack dedicated servers. The bootstrap problem, finding an existing peer in the overlay, remains a challenge to enabling these services for small-scale P2P systems. In large networks, the solution to the bootstrap problem has been the use of dedicated services, though creating and maintaining these systems requires expertise and resources, which constrain their usefulness and make them unappealing for small-scale systems. This paper surveys and summarizes requirements that allow peers potentially constrained by network connectivity to bootstrap small-scale overlays through the use of e...

  10. Cluster based hierarchical resource searching model in P2P network

    Institute of Scientific and Technical Information of China (English)

    Yang Ruijuan; Liu Jian; Tian Jingwen

    2007-01-01

    For the problem of large network load generated by the Gnutella resource-searching model in Peer to Peer (P2P) network, a improved model to decrease the network expense is proposed, which establishes a duster in P2P network,auto-organizes logical layers, and applies a hybrid mechanism of directional searching and flooding. The performance analysis and simulation results show that the proposed hierarchical searching model has availably reduced the generated message load and that its searching-response time performance is as fairly good as that of the Gnutella model.

  11. PyCFTBoot: A flexible interface for the conformal bootstrap

    CERN Document Server

    Behan, Connor

    2016-01-01

    We introduce PyCFTBoot, a wrapper designed to reduce the barrier to entry in conformal bootstrap calculations that require semidefinite programming. Symengine and SDPB are used for the most intensive symbolic and numerical steps respectively. After reviewing the built-in algorithms for conformal blocks, we explain how to use the code through a number of examples that verify past results. As an application, we show that the multi-correlator bootstrap still appears to single out the Wilson-Fisher fixed points as special theories in dimensions between 3 and 4 despite the recent proof that they violate unitarity.

  12. A combined statistical model for multiple motifs search

    Institute of Scientific and Technical Information of China (English)

    Gao Li-Feng; Liu Xin; Guan Shan

    2008-01-01

    Transcription factor binding sites (TFBS) play key roles in genebior 6.8 wavelet expression and regulation. They are short sequence segments with definite structure and can be recognized by the corresponding transcription factors correctly. From the viewpoint of statistics, the candidates of TFBS should be quite different from the segments that are randomly combined together by nucleotide. This paper proposes a combined statistical model for finding overrepresented short sequence segments in different kinds of data set. While the over-represented short sequence segment is described by position weight matrix, the nucleotide distribution at most sites of the segment should be far from the background nucleotide distribution. The central idea of this approach is to search for such kind of signals. This algorithm is tested on 3 data sets, including binding sites data set of cyclic AMP receptor protein in E.coli, PlantProm DB which is a non-redundant collection of proximal promoter sequences from different species, collection of the intergenic sequences of the whole genome of E.Coli. Even though the complexity of these three data sets is quite different, the results show that this model is rather general and sensible.

  13. Il bootstrap. Un'applicazione informatica per un problema di ricampionamento

    OpenAIRE

    Morana, Maria Teresa; Porcu, Mariano

    2002-01-01

    The aim of this paper is to give a simple introduction to the bootstrap techniques showing a basic computer algorithm. The algorithm displays, step by step, how to determinate a bootstrap confidence interval.

  14. Application of ARIMA(1,1,0 Model for Predicting Time Delay of Search Engine Crawlers

    Directory of Open Access Journals (Sweden)

    Jeeva JOSE

    2013-01-01

    Full Text Available World Wide Web is growing at a tremendous rate in terms of the number of visitors and number of web pages. Search engine crawlers are highly automated programs that periodically visit the web and index web pages. The behavior of search engines could be used in analyzing server load, quality of search engines, dynamics of search engine crawlers, ethics of search engines etc. The more the number of visits of a crawler to a web site, the more it contributes to the workload. The time delay between two consecutive visits of a crawler determines the dynamicity of the crawlers. The ARIMA(1,1,0 Model in time series analysis works well with the forecasting of the time delay between the visits of search crawlers at web sites. We considered 5 search engine crawlers, all of which could be modeled using ARIMA(1,1,0.The results of this study is useful in analyzing the server load.

  15. A Hybrid Model Ranking Search Result for Research Paper Searching on Social Bookmarking

    Directory of Open Access Journals (Sweden)

    pijitra jomsri

    2015-11-01

    Full Text Available Social bookmarking and publication sharing systems are essential tools for web resource discovery. The performance and capabilities of search results from research paper bookmarking system are vital. Many researchers use social bookmarking for searching papers related to their topics of interest. This paper proposes a combination of similarity based indexing “tag title and abstract” and static ranking to improve search results. In this particular study, the year of the published paper and type of research paper publication are combined with similarity ranking called (HybridRank. Different weighting scores are employed. The retrieval performance of these weighted combination rankings are evaluated using mean values of NDCG. The results suggest that HybridRank and similarity rank with weight 75:25 has the highest NDCG scores. From the preliminary result of experiment, the combination ranking technique provide more relevant research paper search results. Furthermore the chosen heuristic ranking can improve the efficiency of research paper searching on social bookmarking websites.

  16. A new resampling method for sampling designs without replacement: the doubled half bootstrap

    OpenAIRE

    Antal, Erika; Tillé, Yves

    2016-01-01

    A new and very fast method of bootstrap for sampling without replacement from a finite population is proposed. This method can be used to estimate the variance in sampling with unequal inclusion probabilities and does not require artificial populations or utilization of bootstrap weights. The bootstrap samples are directly selected from the original sample. The bootstrap procedure contains two steps: in the first step, units are selected once with Poisson sampling using the same inclusion pro...

  17. First and second order analysis for periodic random arrays using block bootstrap methods

    OpenAIRE

    Dudek, Anna E.

    2016-01-01

    In the paper row-wise periodically correlated triangular arrays are considered. The period length is assumed to grow in time. The Fourier decomposition of the mean and autocovariance functions for each row of the matrix is presented. To construct bootstrap estimators of the Fourier coefficients two block bootstrap techniques are used. These are the circular version of the Generalized Seasonal Block Bootstrap and the Circular Block Bootstrap. Consistency results for both methods are presented....

  18. Lifetime Labor Supply in a Search Model of Unemployment

    NARCIS (Netherlands)

    L.J.H. Bettendorf (Leon); D.P. Broer (Peter)

    2003-01-01

    textabstractThis paper investigates the age-dependency of participation and unemployment by integrating job search with intertemporal optimizing behavior of finitely-lived households. We find that search frictions and tax rates distort the decisions of older workers to a much larger extent than that

  19. Lifetime labor supply in a search model of unemployment

    NARCIS (Netherlands)

    L.J.H. Bettendorf (Leon); D.P. Broer (Peter)

    2004-01-01

    textabstractThis paper investigates the age-dependency of participation and unemployment by integrating job search with intertemporal optimizing behavior of finitely-lived households. We find that search frictions and tax rates distort the decisions of older workers to a much larger extent than that

  20. Image dataset for testing search and detection models

    NARCIS (Netherlands)

    Toet, A.; Bijl, P.; Valeton, J.M.

    2001-01-01

    The TNO Human Factors Searchû2 image dataset consists of: a set of 44 high-resolution digital color images of different complex natural scenes, the ground truth corresponding to each of these scenes, and the results of psychophysical experiments on each of these images. The images in the Searchû2 da

  1. Bootstrapping Rapidity Anomalous Dimension for Transverse-Momentum Resummation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ye [Fermilab; Zhu, Hua Xing [MIT, Cambridge, CTP

    2016-04-05

    Soft function relevant for transverse-momentum resummation for Drell-Yan or Higgs production at hadron colliders are computed through to three loops in the expansion of strong coupling, with the help of bootstrap technique and supersymmetric decomposition. The corresponding rapidity anomalous dimension is extracted. An intriguing relation between anomalous dimensions for transverse-momentum resummation and threshold resummation is found.

  2. Bootstrapping rapidity anomalous dimension for transverse-momentum resummation

    CERN Document Server

    Li, Ye

    2016-01-01

    Soft function relevant for transverse-momentum resummation for Drell-Yan or Higgs production at hadron colliders are computed through to three loops in the expansion of strong coupling, with the help of bootstrap technique and supersymmetric decomposition. The corresponding rapidity anomalous dimension is extracted. An intriguing relation between anomalous dimensions for transverse-momentum resummation and threshold resummation is found.

  3. Bootstrapping the energy flow in the beginning of life

    NARCIS (Netherlands)

    Hengeveld, R.; Fedonkin, M.A.

    2007-01-01

    This paper suggests that the energy flow on which all living structures depend only started up slowly, the low-energy, initial phase starting up a second, slightly more energetic phase, and so on. In this way, the build up of the energy flow follows a bootstrapping process similar to that found in t

  4. Bootstrap confidence intervals for three-way methods

    NARCIS (Netherlands)

    Kiers, Henk A.L.

    2004-01-01

    Results from exploratory three-way analysis techniques such as CANDECOMP/PARAFAC and Tucker3 analysis are usually presented without giving insight into uncertainties due to sampling. Here a bootstrap procedure is proposed that produces percentile intervals for all output parameters. Special adjustme

  5. Sidecoin: a snapshot mechanism for bootstrapping a blockchain

    OpenAIRE

    Krug, Joseph; Peterson, Jack

    2015-01-01

    Sidecoin is a mechanism that allows a snapshot to be taken of Bitcoin's blockchain. We compile a list of Bitcoin's unspent transaction outputs, then use these outputs and their corresponding balances to bootstrap a new blockchain. This allows the preservation of Bitcoin's economic state in the context of a new blockchain, which may provide new features and technical innovations.

  6. A Statistical Mechanics Approach to Approximate Analytical Bootstrap Averages

    DEFF Research Database (Denmark)

    Malzahn, Dorthe; Opper, Manfred

    2003-01-01

    We apply the replica method of Statistical Physics combined with a variational method to the approximate analytical computation of bootstrap averages for estimating the generalization error. We demonstrate our approach on regression with Gaussian processes and compare our results with averages ob...

  7. Normal Limits, Nonnormal Limits, and the Bootstrap for Quantiles of Dependent Data

    OpenAIRE

    Sharipov, O. Sh.; Wendler, M.

    2012-01-01

    We will show under very weak conditions on differentiability and dependence that the central limit theorem for quantiles holds and that the block bootstrap is weakly consistent. Under slightly stronger conditions, the bootstrap is strongly consistent. Without the differentiability condition, quantiles might have a non-normal asymptotic distribution and the bootstrap might fail.

  8. Using the Descriptive Bootstrap to Evaluate Result Replicability (Because Statistical Significance Doesn't)

    Science.gov (United States)

    Spinella, Sarah

    2011-01-01

    As result replicability is essential to science and difficult to achieve through external replicability, the present paper notes the insufficiency of null hypothesis statistical significance testing (NHSST) and explains the bootstrap as a plausible alternative, with a heuristic example to illustrate the bootstrap method. The bootstrap relies on…

  9. Noncentral limit theorem and the bootstrap for quantiles of dependent data

    OpenAIRE

    Sharipov, Olimjon S.; Wendler, Martin

    2012-01-01

    We will show under minimal conditions on differentiability and dependence that the central limit theorem for quantiles holds and that the block bootstrap is weakly consistent. Under slightly stronger conditions, the bootstrap is strongly consistent. Without the differentiability condition, quantiles might have a non-normal asymptotic distribution and the bootstrap might fail.

  10. RANDOM QUADRATIC-FORMS AND THE BOOTSTRAP FOR U-STATISTICS

    NARCIS (Netherlands)

    DEHLING, H; MIKOSCH, T

    1994-01-01

    We study the bootstrap distribution for U-statistics with special emphasis on the degenerate case. For the Efron bootstrap we give a short proof of the consistency using Mallows' metrics. We also study the i.i.d. weighted bootstrap [GRAPHICS] where (X(i)) and (xi(i)) are two i.i.d. sequences, indepe

  11. Demeter, persephone, and the search for emergence in agent-based models.

    Energy Technology Data Exchange (ETDEWEB)

    North, M. J.; Howe, T. R.; Collier, N. T.; Vos, J. R.; Decision and Information Sciences; Univ. of Chicago; PantaRei Corp.; Univ. of Illinois

    2006-01-01

    In Greek mythology, the earth goddess Demeter was unable to find her daughter Persephone after Persephone was abducted by Hades, the god of the underworld. Demeter is said to have embarked on a long and frustrating, but ultimately successful, search to find her daughter. Unfortunately, long and frustrating searches are not confined to Greek mythology. In modern times, agent-based modelers often face similar troubles when searching for agents that are to be to be connected to one another and when seeking appropriate target agents while defining agent behaviors. The result is a 'search for emergence' in that many emergent or potentially emergent behaviors in agent-based models of complex adaptive systems either implicitly or explicitly require search functions. This paper considers a new nested querying approach to simplifying such agent-based modeling and multi-agent simulation search problems.

  12. Flavour Independent $h^{0}A^{0}$ Search and Two Higgs Doublet Model Interpretation of Neutral Higgs Boson Searches at LEP

    CERN Document Server

    Abbiendi, G; Åkesson, P F; Alexander, G; Allison, J; Amaral, P; Anagnostou, G; Anderson, K J; Asai, S; Axen, D A; Bailey, I; Barberio, E; Barillari, T; Barlow, R J; Batley, J Richard; Bechtle, P; Behnke, T; Bell, K W; Bell, P J; Bella, G; Bellerive, A; Benelli, G; Bethke, Siegfried; Biebel, O; Boeriu, O; Bock, P; Boutemeur, M; Braibant, S; Brown, R M; Burckhart, H J; Campana, S; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Ciocca, C; Csilling, A; Cuffiani, M; Dado, S; de Roeck, A; De Wolf, E A; Desch, Klaus; Dienes, B; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Etzion, E; Fabbri, Franco Luigi; Ferrari, P; Fiedler, F; Fleck, I; Ford, M; Frey, A; Gagnon, P; Gary, J W; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Giunta, M; Goldberg, J; Gross, E; Grunhaus, Jacob; Gruwé, M; Günther, P O; Sen-Gupta, A; Hajdu, C; Hamann, M; Hanson, G G; Harel, A; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, R J; Herten, G; Heuer, R D; Hill, J C; Hoffman, K; Horváth, D; Igo-Kemenes, P; Ishii, K; Jeremie, H; Jovanovic, P; Junk, T R; Kanzaki, J; Karlen, Dean A; Kawagoe, K; Kawamoto, T; Keeler, R K; Kellogg, R G; Kennedy, B W; Kluth, S; Kobayashi, T; Kobel, M; Komamiya, S; Kramer, T; Krieger, P; Von, J H; Krogh, A; Kühl, T; Kupper, M; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Lellouch, D; Letts, J; Levinson, L; Lillich, J; Lloyd, S L; Loebinger, F K; Lü, J; Ludwig, A; Ludwig, J; Mader, W; Marcellini, S; Martin, A J; Masetti, G; Mashimo, T; Mättig, P; McKenna, J A; McPherson, R A; Meijers, F; Menges, W; Merritt, F S; Mes, H; Meyer, N; Michelini, A; Mihara, S; Mikenberg, G; Miller, D J; Mohr, W; Mori, T; Mutter, A; Nagai, K; Nakamura, I; Nanjo, H; Neal, H A; Nisius, R; O'Neale, S W; Oh, A; Oreglia, M J; Orito, S; Pahl, C; Pásztor, G; Pater, J R; Pilcher, J E; Pinfold, J L; Plane, D E; Pooth, O; Przybycien, M B; Quadt, A; Rabbertz, K; Rembser, C; Renkel, P; Roney, J M; Rossi, A M; Rozen, Y; Runge, K; Sachs, K; Saeki, T; Sarkisyan-Grinbaum, E; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schieck, J; Schörner-Sadenius, T; Schröder, M; Schumacher, M; Seuster, R; Shears, T G; Shen, B C; Sherwood, P; Skuja, A; Smith, A M; Sobie, R J; Söldner-Rembold, S; Spanó, F; Stahl, A; Strom, D; Ströhmer, R; Tarem, S; Tasevsky, M; Teuscher, R; Thomson, M A; Torrence, E; Toya, D; Tran, P; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Ujvári, B; Vollmer, C F; Vannerem, P; Vertesi, R; Verzocchi, M; Voss, H; Vossebeld, Joost Herman; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wilson, G W; Wilson, J A; Wolf, G; Wyatt, T R; Yamashita, S; Zer-Zion, D; Zivkovic, L

    2005-01-01

    Upper limits on the cross-section of the pair-production process e+e- -> h0A0 assuming 100% decays into hadrons, are derived from a new search for the h0A0 -> hadrons topology, independent of the hadronic flavour of the decay products. Searches for the neutral Higgs bosons h0 and A0, are used to obtain constraints on the Type II Two Higgs Doublet Model (2HDM(11)) with no CP violation in the Higgs sector and no additional non Standard Model particles besides the five Higgs bosons. The analysis combines LEP1 and LEP2 data collected with the OPAL detctor up to the highest available centre-of-mass energies. The searches are sensitive to the h0, A0 -> qq, gg,tau+tau- and h0 -> A0A0 decay modes of the Higgs bosons. The 2HDM(II) parameter space is explored in a detailed scan. Large regions of the 2HDM(II) parameter space are excluded at the 95% CL in the (mh, mA), (mh, tanb) and (mA, tanb) planes, using both direct neutral Higgs boson searches and indirect limits derived from Standard Model high precision measuremen...

  13. The probit choice model under sequential search with an application to online retailing

    NARCIS (Netherlands)

    Bronnenberg, Bart; Kim, Jun B.; Albuquerque, P.

    2016-01-01

    We develop a probit choice model under optimal sequential search and apply it to the study of aggregate demand of consumer durable goods. In our joint model of search and choice, we derive a semi-closed form expression for the probability of choice that obeys the full set of restrictions imposed by

  14. A new model of information behaviour based on the Search Situation Transition schema Information searching, Information behaviour, Behavior, Information retrieval, Information seeking

    Directory of Open Access Journals (Sweden)

    Nils Pharo

    2004-01-01

    Full Text Available This paper presents a conceptual model of information behaviour. The model is part of the Search Situation Transition method schema. The method schema is developed to discover and analyse interplay between phenomena traditionally analysed as factors influencing either information retrieval or information seeking. In this paper the focus is on the model's five main categories: the work task, the searcher, the social/organisational environment, the search task, and the search process. In particular, the search process and its sub-categories search situation and transition and the relationship between these are discussed. To justify the method schema an empirical study was designed according to the schema's specifications. In the paper a subset of the study is presented analysing the effects of work tasks on Web information searching. Findings from this small-scale study indicate a strong relationship between the work task goal and the level of relevance used for judging resources during search processes.

  15. Model for Auditing Search Engine Optimization for E-business

    OpenAIRE

    Schooner, Patrick

    2010-01-01

    E-commerce combines web technology with business economics. As of the last 10 years, online visibility for such online enterprises now heavily rely on the relationship between the own online sales platform and Search Engines for improved traffic consisting of presumable customers with the intent of acquiring products or services related to the customers’ needs. In 2008 an Internet behavioural analysis showed that over 90% percent of Swedish internet users make use of search engines at least o...

  16. Bootstrap study of genome-enabled prediction reliabilities using haplotype blocks across Nordic Red cattle breeds.

    Science.gov (United States)

    Cuyabano, B C D; Su, G; Rosa, G J M; Lund, M S; Gianola, D

    2015-10-01

    This study compared the accuracy of genome-enabled prediction models using individual single nucleotide polymorphisms (SNP) or haplotype blocks as covariates when using either a single breed or a combined population of Nordic Red cattle. The main objective was to compare predictions of breeding values of complex traits using a combined training population with haplotype blocks, with predictions using a single breed as training population and individual SNP as predictors. To compare the prediction reliabilities, bootstrap samples were taken from the test data set. With the bootstrapped samples of prediction reliabilities, we built and graphed confidence ellipses to allow comparisons. Finally, measures of statistical distances were used to calculate the gain in predictive ability. Our analyses are innovative in the context of assessment of predictive models, allowing a better understanding of prediction reliabilities and providing a statistical basis to effectively calibrate whether one prediction scenario is indeed more accurate than another. An ANOVA indicated that use of haplotype blocks produced significant gains mainly when Bayesian mixture models were used but not when Bayesian BLUP was fitted to the data. Furthermore, when haplotype blocks were used to train prediction models in a combined Nordic Red cattle population, we obtained up to a statistically significant 5.5% average gain in prediction accuracy, over predictions using individual SNP and training the model with a single breed. PMID:26233439

  17. Search for the Standard Model Higgs Boson in the $WH \\to \\ell \

    Energy Technology Data Exchange (ETDEWEB)

    Nagai, Yoshikazu [Univ. of Tsukuba (Japan)

    2010-02-01

    We have searched for the Standard Model Higgs boson in the WH → lvbb channel in 1.96 TeV pp collisions at CDF. This search is based on the data collected by March 2009, corresponding to an integrated luminosity of 4.3 fb-1. The W H channel is one of the most promising channels for the Higgs boson search at Tevatron in the low Higgs boson mass region.

  18. Progress Toward Steady State Tokamak Operation Exploiting the high bootstrap current fraction regime

    Science.gov (United States)

    Ren, Q.

    2015-11-01

    Recent DIII-D experiments have advanced the normalized fusion performance of the high bootstrap current fraction tokamak regime toward reactor-relevant steady state operation. The experiments, conducted by a joint team of researchers from the DIII-D and EAST tokamaks, developed a fully noninductive scenario that could be extended on EAST to a demonstration of long pulse steady-state tokamak operation. Fully noninductive plasmas with extremely high values of the poloidal beta, βp >= 4 , have been sustained at βT >= 2 % for long durations with excellent energy confinement quality (H98y,2 >= 1 . 5) and internal transport barriers (ITBs) generated at large minor radius (>= 0 . 6) in all channels (Te, Ti, ne, VTf). Large bootstrap fraction (fBS ~ 80 %) has been obtained with high βp. ITBs have been shown to be compatible with steady state operation. Because of the unusually large ITB radius, normalized pressure is not limited to low βN values by internal ITB-driven modes. βN up to ~4.3 has been obtained by optimizing the plasma-wall distance. The scenario is robust against several variations, including replacing some on-axis with off-axis neutral beam injection (NBI), adding electron cyclotron (EC) heating, and reducing the NBI torque by a factor of 2. This latter observation is particularly promising for extension of the scenario to EAST, where maximum power is obtained with balanced NBI injection, and to a reactor, expected to have low rotation. However, modeling of this regime has provided new challenges to state-of-the-art modeling capabilities: quasilinear models can dramatically underpredict the electron transport, and the Sauter bootstrap current can be insufficient. The analysis shows first-principle NEO is in good agreement with experiments for the bootstrap current calculation and ETG modes with a larger saturated amplitude or EM modes may provide the missing electron transport. Work supported in part by the US DOE under DE-FC02-04ER54698, DE-AC52-07NA

  19. Propensity to Search: Common, Leisure, and Labor Models of Consumer Behavior

    Directory of Open Access Journals (Sweden)

    Sergey MALAKHOV

    2015-05-01

    Full Text Available The analysis of the propensity to search specifies the “common” or the ordinary model of consumer behavior based on the synthesis of the neoclassical approach with satisficing concept, and “leisure” and “labor” models of behavior that represent different combinations of conspicuous consumption, leisure, and labor. While the “common model” of behavior demonstrates a moderate propensity to search, “leisure” and “labor” models of consumer behavior exhibit vigorous propensities to search that results in purchase of unnecessary items and therefore in overconsumption. This trend is also presented in home production where vigorous propensity to search takes the form of the vigorous propensity to produce at home. The analysis of trends in allocation of time provides grounds for the assumption that men have more accentuated propensity to search and to produce at home than women that results in overconsumption of unnecessary items.

  20. A model for the evaluation of search queries in medical bibliographic sources

    NARCIS (Netherlands)

    Verhoeven, A A; Boendermaker, P M; Boerma, E J; Meyboom-de Jong, B

    1999-01-01

    The aim of this study was to develop a model to evaluate the retrieval quality of search queries performed by Dutch general practitioners using the printed Index Medicus, MEDLINE on CD-ROM, and MEDLINE through GRATEFUL MED. Four search queries related to general practice were formulated for a contin

  1. Search for Physics Beyond the Standard Model at BaBar and Belle

    Directory of Open Access Journals (Sweden)

    Calderini G.

    2012-06-01

    Full Text Available Recent results on the search for new physics at BaBar and Belle B-factories are presented. The search for a light Higgs boson produced in the decay of different γ resonances is shown. In addition, recent measurements aimed to discover invisible final states produced by new physics mechanisms beyond the standard model are presented.

  2. Searches for physics beyond the Standard Model using jet-based resonances with the ATLAS Detector

    CERN Document Server

    Frate, Meghan; The ATLAS collaboration

    2016-01-01

    Run2 of the LHC, with its increased center-of-mass energy, is an unprecedented opportunity to discover physics beyond the Standard Model. One interesting possibility to conduct such searches is to use resonances based on jets. The latest search results from the ATLAS experiment, based on either inclusive or heavy-flavour jets, will be presented.

  3. The Value of Moderate Obsession: Insights from a New Model of Organizational Search

    OpenAIRE

    Cattani, Gino; Dorsch, Alex; Winter, Sidney G.

    2007-01-01

    This study presents a new model of search on a rugged landscape, which employs modeling techniques from fractal geometry rather than the now-familiar NK modeling technique. In our simulations, firms search locally in a two-dimensional fitness landscape, choosing moves in a way that responds both to local payoff considerations and to a more global sense of opportunity represented by a firm-specific preferred direction. The latter concept provides a very simple device for introducing cognitive ...

  4. Czech labour market through the lens of a search and matching DSGE model

    OpenAIRE

    Němec Daniel

    2011-01-01

    This contribution reveals some important structural properties of the Czech labour market in the last fifteen years and evaluates possible changes within this period. A small search and matching model incorporated into standard macroeconomic dynamic stochastic general equilibrium model is estimated using Bayesian techniques. The results show that search and matching aspect provides satisfactory description of employment flows in the Czech economy. Model estimates provide convincing evidence t...

  5. A Sorting Method of Meta-search Based on User Web Page Interactive Model

    Institute of Scientific and Technical Information of China (English)

    Zongli Jiang; Tengyu Zhang

    2012-01-01

    Nowadays, there is a problem in most meta-search engines that many web pages searched have nothing to do with users' expectations. We introduce a new user web page interactive model under the framework ofmeta search, which analyzes users' action to get users' interests and storages them, and update these information with users' feedback. Meanwhile this model analyzes user records stored in web, attaches labels to the web page with statistics of user interest. We calculate the similarity about user and web page with the information from model and add similarity to scores of web pages. The experimental results reveal that this method can improve the relevance of the information retrieval.

  6. Bootstrap bound for conformal multi-flavor QCD on lattice

    CERN Document Server

    Nakayama, Yu

    2016-01-01

    The recent work by Iha et al shows an upper bound on mass anomalous dimension $\\gamma_m$ of multi-flavor massless QCD at the renormalization group fixed point from the conformal bootstrap in $SU(N_F)_V$ symmetric conformal field theories under the assumption that the fixed point is realizable with the lattice regularization based on staggered fermions. We show that the almost identical but slightly stronger bound applies to the regularization based on Wilson fermions (or domain wall fermions) by studying the conformal bootstrap in $SU(N_f)_L \\times SU(N_f)_R$ symmetric conformal field theories. For $N_f=8$, our bound implies $\\gamma_m < 1.31$ to avoid dangerously irrelevant operators that are not compatible with the lattice symmetry.

  7. A bootstrap lunar base: Preliminary design review 2

    Science.gov (United States)

    1987-01-01

    A bootstrap lunar base is the gateway to manned solar system exploration and requires new ideas and new designs on the cutting edge of technology. A preliminary design for a Bootstrap Lunar Base, the second provided by this contractor, is presented. An overview of the work completed is discussed as well as the technical, management, and cost strategies to complete the program requirements. The lunar base design stresses the transforming capabilities of its lander vehicles to aid in base construction. The design also emphasizes modularity and expandability in the base configuration to support the long-term goals of scientific research and profitable lunar resource exploitation. To successfully construct, develop, and inhabit a permanent lunar base, however, several technological advancements must first be realized. Some of these technological advancements are also discussed.

  8. Bootstrap bound for conformal multi-flavor QCD on lattice

    Science.gov (United States)

    Nakayama, Yu

    2016-07-01

    The recent work by Iha et al. shows an upper bound on mass anomalous dimension γ m of multi-flavor massless QCD at the renormalization group fixed point from the conformal bootstrap in SU( N F ) V symmetric conformal field theories under the assumption that the fixed point is realizable with the lattice regularization based on staggered fermions. We show that the almost identical but slightly stronger bound applies to the regularization based on Wilson fermions (or domain wall fermions) by studying the conformal bootstrap in SU( N f ) L × SU( N f ) R symmetric conformal field theories. For N f = 8, our bound implies γ m < 1 .31 to avoid dangerously irrelevant operators that are not compatible with the lattice symmetry.

  9. Neutral Higgs bosons in the standard model and in the minimal supersymmetric model: Searches at LEP

    Indian Academy of Sciences (India)

    P Igo-Kemenes

    2004-03-01

    During the twelve years of operation of the $e^{+}e^{-}$ collider LEP, the associated collaborations, ALEPH, DELPHI, L3 and OPAL, have extensively searched for Higgs bosons over a broad range of masses. We present the final results from LEP for the standard model Higgs boson which are obtained from a statistical combination of the data from the four experiments. We also present preliminary combined results for neutral Higgs bosons in the minimal supersymmetric model (MSSM) where the Higgs sector is assumed to be CP invariant. Finally, we discuss an alternative MSSM scenario including CP violation in the Higgs sector.

  10. Non-critical string, Liouville theory and geometric bootstrap hypothesis

    CERN Document Server

    Hadasz, L; Hadasz, Leszek; Jaskolski, Zbigniew

    2003-01-01

    Basing on the standard construction of critical string amplitudes we analyze properties of the longitudinal sector of the non-critical Nambu-Goto string. We demonstrate that it cannot be described by standard (in the sense of BPZ) conformal field theory. As an alternative we propose a new version of the geometric approach to Liouville theory and formulate its basic consistency condition - the geometric bootstrap equation.

  11. Bootstrap and the physical values of $\\pi N$ resonance parameters

    OpenAIRE

    Semenov-Tian-Shansky, Kirill M.; Vereshagin, Alexander V.; Vereshagin, Vladimir V.

    2007-01-01

    This is the 6th paper in the series developing the formalism to manage the effective scattering theory of strong interactions. Relying on the theoretical scheme suggested in our previous publications we concentrate here on the practical aspect and apply our technique to the elastic pion-nucleon scattering amplitude. We test numerically the pion-nucleon spectrum sum rules that follow from the tree level bootstrap constraints. We show how these constraints can be used to estimate the tensor and...

  12. Addressing the P2P Bootstrap Problem for Small Networks

    OpenAIRE

    Wolinsky, David Isaac; Juste, Pierre St.; Boykin, P. Oscar; Figueiredo, Renato

    2010-01-01

    P2P overlays provide a framework for building distributed applications consisting of few to many resources with features including self-configuration, scalability, and resilience to node failures. Such systems have been successfully adopted in large-scale services for content delivery networks, file sharing, and data storage. In small-scale systems, they can be useful to address privacy concerns and for network applications that lack dedicated servers. The bootstrap problem, finding an existi...

  13. Bootstrapping a Five-Loop Amplitude from Steinmann Relations

    CERN Document Server

    Caron-Huot, Simon; McLeod, Andrew; von Hippel, Matt

    2016-01-01

    The analytic structure of scattering amplitudes is restricted by Steinmann relations, which enforce the vanishing of certain discontinuities of discontinuities. We show that these relations dramatically simplify the function space for the hexagon function bootstrap in planar maximally supersymmetric Yang-Mills theory. Armed with this simplification, along with the constraints of dual conformal symmetry and Regge exponentiation, we obtain the complete five-loop six-particle amplitude.

  14. Comparison Of Modified Bootstrap And Conventional Sensitometry In Medical Radiography

    Science.gov (United States)

    Bednarek, Daniel R.; Rudin, Stephen

    1980-08-01

    A new modified bootstrap approach to sensitometry is presented which provides H and D curves that show almost exact agreement with those obtained using conventional methods. Two bootstrap techniques are described; both involve a combination of inverse-square and step-ped wedge modulation of the radiation field and provide intensity-scale sensitometric curves as appropriate for medical radiography. H and D curves obtained with these modified techniques are compared with those obtained for screen-film combinations using inverse-square sensitometry as well as with those obtained for direct x-ray film using time-scale sensitometry. The stepped-wedge of the Wisconsin X-Ray Test Cassette was used in the boot-strap approach since it provides sufficient exposure latitude to encompass the useful den-sity range of medical x-ray film. This approach makes radiographic sensitometry quick and convenient, allowing accurate characteristic curves to be obtained for any screen-film cassette using standard diagnostic equipment.

  15. Quantitative evaluation of PET image using event information bootstrap

    Science.gov (United States)

    Song, Hankyeol; Kwak, Shin Hye; Kim, Kyeong Min; Kang, Joo Hyun; Chung, Yong Hyun; Woo, Sang-Keun

    2016-04-01

    The purpose of this study was to enhance the effect in the PET image quality according to event bootstrap of small animal PET data. In order to investigate the time difference condition, realigned sinograms were generated from randomly sampled data set using bootstrap. List-mode data was obtained from small animal PET scanner for Ge-68 30 sec, Y-90 20 min and Y-90 60 min. PET image was reconstructed by Ordered Subset Expectation Maximization(OSEM) 2D with the list-mode format. Image analysis was investigated by Signal to Noise Ratio(SNR) of Ge-68 and Y-90 image. Non-parametric resampled PET image SNR percent change for the Ge-68 30 sec, Y-90 60 min, and Y-90 20 min was 1.69 %, 7.03 %, and 4.78 %, respectively. SNR percent change of non-parametric resampled PET image with time difference condition was 1.08 % for the Ge-68 30 sec, 6.74 % for the Y-90 60 min and 10.94 % for the Y-90 29 min. The result indicated that the bootstrap with time difference condition had a potential to improve a noisy Y-90 PET image quality. This method should be expected to reduce Y-90 PET measurement time and to enhance its accuracy.

  16. On Bootstrap Tests of Symmetry About an Unknown Median.

    Science.gov (United States)

    Zheng, Tian; Gastwirth, Joseph L

    2010-07-01

    It is important to examine the symmetry of an underlying distribution before applying some statistical procedures to a data set. For example, in the Zuni School District case, a formula originally developed by the Department of Education trimmed 5% of the data symmetrically from each end. The validity of this procedure was questioned at the hearing by Chief Justice Roberts. Most tests of symmetry (even nonparametric ones) are not distribution free in finite sample sizes. Hence, using asymptotic distribution may not yield an accurate type I error rate or/and loss of power in small samples. Bootstrap resampling from a symmetric empirical distribution function fitted to the data is proposed to improve the accuracy of the calculated p-value of several tests of symmetry. The results show that the bootstrap method is superior to previously used approaches relying on the asymptotic distribution of the tests that assumed the data come from a normal distribution. Incorporating the bootstrap estimate in a recently proposed test due to Miao, Gel and Gastwirth (2006) preserved its level and shows it has reasonable power properties on the family of distribution evaluated.

  17. Using Intent Information to Model User Behavior in Diversified Search

    NARCIS (Netherlands)

    A. Chuklin; P. Serdyukov; M. de Rijke

    2013-01-01

    A result page of a modern commercial search engine often contains documents of different types targeted to satisfy different user intents (news, blogs, multimedia). When evaluating system performance and making design decisions we need to better understand user behavior on such result pages. To addr

  18. Advertising and consumer search in a duopoly model

    NARCIS (Netherlands)

    Janssen, Maarten C. W.; Non, Marielle C.

    2008-01-01

    We consider a duopoly in a homogenous goods market where part of the consumers are ex ante uninformed about prices. Information can come through two different channels: advertising and sequential consumer search. We arrive at the following results. First, there is no monotone relationship between pr

  19. Central Limit Theorem and bootstrap procedure for Wasserstein's barycenter variations and application to structural relationships between distributions

    OpenAIRE

    Del Barrio, Eustasio; Lescornel, Hélène; Loubes, Jean-Michel

    2016-01-01

    Wasserstein barycenters and variance-like criterion using Wasser-stein distance are used in many problems to analyze the homogeneity of collections of distributions and structural relationships between the observations. We propose the estimation of the quantiles of the empirical process of the Wasserstein's variation using a bootstrap procedure. Then we use these results for statistical inference on a distribution registration model for general deformation functions. The tests are based on th...

  20. Time-Scale Block Bootstrap tests for non Gaussian finite variance self-similar processes with stationary increments

    OpenAIRE

    Wendt, Herwig; Abry, Patrice

    2007-01-01

    Scaling analysis is nowadays becoming a standard tool in statistical signal processing. It mostly consists of estimating scaling attributes which in turns are involved in standard tasks such as detection, identification or classification. Recently, we proposed that confidence interval or hypothesis test design for scaling analysis could be based on non parametric bootstrap approaches. We showed that such procedures are efficient to decide whether data are better modeled with Gaussian fraction...

  1. A Neurocomputational Theory of how Explicit Learning Bootstraps Early Procedural Learning

    Directory of Open Access Journals (Sweden)

    Erick Joseph Paul

    2013-12-01

    Full Text Available It is widely accepted that human learning and memory is mediated by multiple memory systems that are each best suited to different requirements and demands. Within the domain of categorization, at least two systems are thought to facilitate learning: an explicit (declarative system depending largely on the prefrontal cortex, and a procedural (non-declarative system depending on the basal ganglia. Substantial evidence suggests that each system is optimally suited to learn particular categorization tasks. However, it remains unknown precisely how these systems interact to produce optimal learning and behavior. In order to investigate this issue, the present research evaluated the progression of learning through simulation of categorization tasks using COVIS, a well-known model of human category learning that includes both explicit and procedural learning systems. Specifically, the model's parameter space was thoroughly explored in procedurally learned categorization tasks across a variety of conditions and architectures to identify plausible interaction architectures. The simulation results support the hypothesis that one-way interaction between the systems occurs such that the explicit system "bootstraps" learning early on in the procedural system. Thus, the procedural system initially learns a suboptimal strategy employed by the explicit system and later refines its strategy. This bootstrapping could be from cortical-striatal projections that originate in premotor or motor regions of cortex, or possibly by the explicit system’s control of motor responses through basal ganglia-mediated loops.

  2. A neurocomputational theory of how explicit learning bootstraps early procedural learning.

    Science.gov (United States)

    Paul, Erick J; Ashby, F Gregory

    2013-01-01

    It is widely accepted that human learning and memory is mediated by multiple memory systems that are each best suited to different requirements and demands. Within the domain of categorization, at least two systems are thought to facilitate learning: an explicit (declarative) system depending largely on the prefrontal cortex, and a procedural (non-declarative) system depending on the basal ganglia. Substantial evidence suggests that each system is optimally suited to learn particular categorization tasks. However, it remains unknown precisely how these systems interact to produce optimal learning and behavior. In order to investigate this issue, the present research evaluated the progression of learning through simulation of categorization tasks using COVIS, a well-known model of human category learning that includes both explicit and procedural learning systems. Specifically, the model's parameter space was thoroughly explored in procedurally learned categorization tasks across a variety of conditions and architectures to identify plausible interaction architectures. The simulation results support the hypothesis that one-way interaction between the systems occurs such that the explicit system "bootstraps" learning early on in the procedural system. Thus, the procedural system initially learns a suboptimal strategy employed by the explicit system and later refines its strategy. This bootstrapping could be from cortical-striatal projections that originate in premotor or motor regions of cortex, or possibly by the explicit system's control of motor responses through basal ganglia-mediated loops. PMID:24385962

  3. Using minimum bootstrap support for splits to construct confidence regions for trees

    Directory of Open Access Journals (Sweden)

    Edward Susko

    2006-01-01

    Full Text Available Many of the estimated topologies in phylogenetic studies are presented with the bootstrap support for each of the splits in the topology indicated. If phylogenetic estimation is unbiased, high bootstrap support for a split suggests that there is a good deal of certainty that the split actually is present in the tree and low bootstrap support suggests that one or more of the taxa on one side of the estimated split might in reality be located with taxa on the other side. In the latter case the follow-up questions about how many and which of the taxa could reasonably be incorrectly placed as well as where they might alternatively be placed are not addressed through the presented bootstrap support. We present here an algorithm that finds the set of all trees with minimum bootstrap support for their splits greater than some given value. The output is a ranked list of trees, ranked according to the minimum bootstrap supports for splits in the trees. The number of such trees and their topologies provides useful supplementary information in bootstrap analyses about the reasons for low bootstrap support for splits. We also present ways of quantifying low bootstrap support by considering the set of all topologies with minimum bootstrap greater than some quantity as providing a confidence region of topologies. Using a double bootstrap we are able to choose a cutoff so that the set of topologies with minimum bootstrap support for a split greater than that cutoff gives an approximate 95% confidence region. As with bootstrap support one advantage of the methods is that they are generally applicable to the wide variety of phylogenetic estimation methods.

  4. Human search for a target on a textured background is consistent with a stochastic model.

    Science.gov (United States)

    Clarke, Alasdair D F; Green, Patrick; Chantler, Mike J; Hunt, Amelia R

    2016-05-01

    Previous work has demonstrated that search for a target in noise is consistent with the predictions of the optimal search strategy, both in the spatial distribution of fixation locations and in the number of fixations observers require to find the target. In this study we describe a challenging visual-search task and compare the number of fixations required by human observers to find the target to predictions made by a stochastic search model. This model relies on a target-visibility map based on human performance in a separate detection task. If the model does not detect the target, then it selects the next saccade by randomly sampling from the distribution of saccades that human observers made. We find that a memoryless stochastic model matches human performance in this task. Furthermore, we find that the similarity in the distribution of fixation locations between human observers and the ideal observer does not replicate: Rather than making the signature doughnut-shaped distribution predicted by the ideal search strategy, the fixations made by observers are best described by a central bias. We conclude that, when searching for a target in noise, humans use an essentially random strategy, which achieves near optimal behavior due to biases in the distributions of saccades we have a tendency to make. The findings reconcile the existence of highly efficient human search performance with recent studies demonstrating clear failures of optimality in single and multiple saccade tasks. PMID:27145531

  5. Simplified models vs. effective field theory approaches in dark matter searches

    Science.gov (United States)

    De Simone, Andrea; Jacques, Thomas

    2016-07-01

    In this review we discuss and compare the usage of simplified models and Effective Field Theory (EFT) approaches in dark matter searches. We provide a state of the art description on the subject of EFTs and simplified models, especially in the context of collider searches for dark matter, but also with implications for direct and indirect detection searches, with the aim of constituting a common language for future comparisons between different strategies. The material is presented in a form that is as self-contained as possible, so that it may serve as an introductory review for the newcomer as well as a reference guide for the practitioner.

  6. Simplified Models vs. Effective Field Theory Approaches in Dark Matter Searches

    CERN Document Server

    De Simone, Andrea

    2016-01-01

    In this review we discuss and compare the usage of simplified models and Effective Field Theory (EFT) approaches in dark matter searches. We provide a state of the art description on the subject of EFTs and simplified models, especially in the context of collider searches for dark matter, but also with implications for direct and indirect detection searches, with the aim of constituting a common language for future comparisons between different strategies. The material is presented in a form that is as self-contained as possible, so that it may serve as an introductory review for the newcomer as well as a reference guide for the practitioner.

  7. Model-independent search for new physics at D0 experiment

    Indian Academy of Sciences (India)

    Md Naimuddin

    2012-11-01

    Finding the evidence of new physics beyond the Standard Model is one of the primary goals of RunII of the Tevatron. Many dedicated searches for new physics are ongoing at the Tevatron but in order to broaden the scope and maximize the chances of finding the new physics, we also search in a model-independent way. The results of such searches for indications of new physics at the electroweak scale are presented using data collected using the D0 detector from $p\\bar{p}$-interactions at $\\sqrt{s} = 1.96$ TeV.

  8. Sleuth at CDF: A Quasi-model-independent search for new electroweak scale physics

    Energy Technology Data Exchange (ETDEWEB)

    Choudalakis, Georgios; /MIT, LNS

    2007-10-01

    These proceedings describe Sleuth, a quasi-model-independent search strategy targeting new electroweak scale physics, and its application to 927 pb{sup -1} of CDF II data. Exclusive final states are analyzed for an excess of data beyond the Standard Model prediction at large summed scalar transverse momentum. This analysis of high-pT data represents one of the most encompassing searches so far conducted for new physics at the energy frontier.

  9. Modeling Movements in Oil, Gold, Forex and Market Indices using Search Volume Index and Twitter Sentiments

    OpenAIRE

    Tushar Rao; Saket Srivastava

    2012-01-01

    Study of the forecasting models using large scale microblog discussions and the search behavior data can provide a good insight for better understanding the market movements. In this work we collected a dataset of 2 million tweets and search volume index (SVI from Google) for a period of June 2010 to September 2011. We perform a study over a set of comprehensive causative relationships and developed a unified approach to a model for various market securities like equity (Dow Jones Industrial ...

  10. Searches for physics beyond the Standard Model at the Tevatron

    Indian Academy of Sciences (India)

    Alberto Annovi; for the CDF and D0 Collaborations

    2012-10-01

    During the last 10 years, the Fermilab Tevatron has produced $p \\bar{p}$ collision at a centre-of-mass energy of 1.96 TeV that the CDF and DO Collaborations have scrutinized looking for new physics in a wide range of final states. Here, recent updates of new physics searches are reported using a data sample of up to 9 fb-1

  11. Thermomechanical analysis of long-term global modal and local deformation measurements of the Kishwaukee Bridge using the bootstrap

    Institute of Scientific and Technical Information of China (English)

    George M. Lloyd; Ming L. Wang; Xuan Wang

    2004-01-01

    In this paper we present a comparative analysis of global frequency and local deformation data for a large concrete bridge. The asymptotic probability distributions of the central statistics are presented, and compared with empirical bootstrap estimates. Bootstrapped distributions are calculated from reference data obtained during 1999-2000 and used to develop change-point alarm criteria for the structure, using reasonable sensitivity measures developed from FEM simulations and structural analysis. The implications of the frequency data are discussed in conjunction with the strain and displacement measurements in order to discern if the load carrying capacity of the bridge has been affected. The critical need for more advanced temperature compensation models for large structures continually in thermal disequilibrium is discussed.

  12. The health belief model and consumer information searches: toward an integrated model.

    Science.gov (United States)

    Risker, D C

    1996-01-01

    Some health data organizations (HDOs) are producing consumer-level health services information. National reform proposals would suggest that competition between health plans will be developed through the use of outcome information. Policy makers have paid little attention to how consumers might use that information or how that information might be most effectively packaged for consumer use. This paper argues that marketing literature developed over the last ten to fifteen years could prove to be an informative resource for policy makers and the health services provider community alike. This paper suggests that combining a consumer decision model (CDM) with the health belief model (HBM) will provide an important step toward an increased understanding of consumer information search behavior. This integrated model could form the basis of future research in this important area.

  13. Bootstrap inversion for Pn wave velocity in North-Western Italy

    Directory of Open Access Journals (Sweden)

    C. Eva

    1997-06-01

    Full Text Available An inversion of Pn arrival times from regional distance earthquakes (180-800 km, recorded by 94 seismic stations operating in North-Western Italy and surrounding areas, was carried out to image lateral variations of P-wave velocity at the crust-mantle boundary, and to estimate the static delay time at each station. The reliability of the obtained results was assessed using both synthetic tests and the bootstrap Monte Carlo resampling technique. Numerical simulations demonstrated the existence of a trade-off between cell velocities and estimated station delay times along the edge of the model. Bootstrap inversions were carried out to determine the standard deviation of velocities and time terms. Low Pn velocity anomalies are detected beneath the outer side of the Alps (-6% and the Western Po plain (-4% in correspondence with two regions of strong crustal thickening and negative Bouguer anomaly. In contrast, high Pn velocities are imaged beneath the inner side of the Alps (+4% indicating the presence of high velocity and density lower crust-upper mantle. The Ligurian sea shows high Pn velocities close to the Ligurian coastlines (+3% and low Pn velocities (-1.5% in the middle of the basin in agreement with the upper mantle velocity structure revealed by seismic refraction profiles.

  14. A Pilot Investigation of the Relationship between Climate Variability and Milk Compounds under the Bootstrap Technique

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Marami Milani

    2015-09-01

    Full Text Available This study analyzes the linear relationship between climate variables and milk components in Iran by applying bootstrapping to include and assess the uncertainty. The climate parameters, Temperature Humidity Index (THI and Equivalent Temperature Index (ETI are computed from the NASA-Modern Era Retrospective-Analysis for Research and Applications (NASA-MERRA reanalysis (2002–2010. Milk data for fat, protein (measured on fresh matter bases, and milk yield are taken from 936,227 milk records for the same period, using cows fed by natural pasture from April to September. Confidence intervals for the regression model are calculated using the bootstrap technique. This method is applied to the original times series, generating statistically equivalent surrogate samples. As a result, despite the short time data and the related uncertainties, an interesting behavior of the relationships between milk compound and the climate parameters is visible. During spring only, a weak dependency of milk yield and climate variations is obvious, while fat and protein concentrations show reasonable correlations. In summer, milk yield shows a similar level of relationship with ETI, but not with temperature and THI. We suggest this methodology for studies in the field of the impacts of climate change and agriculture, also environment and food with short-term data.

  15. Impurities in a non-axisymmetric plasma: Transport and effect on bootstrap current

    Energy Technology Data Exchange (ETDEWEB)

    Mollén, A., E-mail: albertm@chalmers.se [Department of Applied Physics, Chalmers University of Technology, Göteborg (Sweden); Max-Planck-Institut für Plasmaphysik, 17491 Greifswald (Germany); Landreman, M. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States); Smith, H. M.; Helander, P. [Max-Planck-Institut für Plasmaphysik, 17491 Greifswald (Germany); Braun, S. [Max-Planck-Institut für Plasmaphysik, 17491 Greifswald (Germany); German Aerospace Center, Institute of Engineering Thermodynamics, Pfaffenwaldring 38-40, D-70569 Stuttgart (Germany)

    2015-11-15

    Impurities cause radiation losses and plasma dilution, and in stellarator plasmas the neoclassical ambipolar radial electric field is often unfavorable for avoiding strong impurity peaking. In this work we use a new continuum drift-kinetic solver, the SFINCS code (the Stellarator Fokker-Planck Iterative Neoclassical Conservative Solver) [M. Landreman et al., Phys. Plasmas 21, 042503 (2014)] which employs the full linearized Fokker-Planck-Landau operator, to calculate neoclassical impurity transport coefficients for a Wendelstein 7-X (W7-X) magnetic configuration. We compare SFINCS calculations with theoretical asymptotes in the high collisionality limit. We observe and explain a 1/ν-scaling of the inter-species radial transport coefficient at low collisionality, arising due to the field term in the inter-species collision operator, and which is not found with simplified collision models even when momentum correction is applied. However, this type of scaling disappears if a radial electric field is present. We also use SFINCS to analyze how the impurity content affects the neoclassical impurity dynamics and the bootstrap current. We show that a change in plasma effective charge Z{sub eff} of order unity can affect the bootstrap current enough to cause a deviation in the divertor strike point locations.

  16. Asal Bileşenler Analizine Bootstrap Yaklaşımı

    OpenAIRE

    AKTÜKÜN, Dr. Aylin

    2011-01-01

    Bu çalışmada, bootstrap yöntemlerin asal bileşenler analizine uygulanma sürecini sunduk. Hipotetik bir veri ile asal bileşenler analizinde başvurulan bazı güven aralıklarının bootstrap yöntemlerle nasıl gerçekleştirilebileceğini gösterdik. Makaledeki tüm bootstrap süreçleri Mathematica dilinde yazdığımız bir programla gerçekleştirdik. Anahtar Kelimeler: Asal bileşenler analizi, Bootstrap, Bootstrap kantiller, Bootstrap Güven Aralıkları, Mathematica.  ABSRACT In this paper, we apply ...

  17. Wages, Training, and Job Turnover in a Search-Matching Model

    DEFF Research Database (Denmark)

    Rosholm, Michael; Nielsen, Michael Svarer

    1999-01-01

    In this paper we extend a job search-matching model with firm-specific investments in training developed by Mortensen (1998) to allow for different offer arrival rates in employment and unemployment. The model by Mortensen changes the original wage posting model (Burdett and Mortensen, 1998) in t...

  18. Multilingual probabilistic topic modeling and its applications in Web mining and search

    OpenAIRE

    Vulic, Ivan; Moens, Marie-Francine

    2014-01-01

    Multilingual topic models are a fairly novel group of unsupervised, language-independent and generative machine learning models. This tutorial covers all key aspects of their probabilistic framework and demonstrates how to easily integrate these models into frameworks for cross-lingual and multilingual Web mining and search.

  19. Beyond standard model Higgs boson searches in the ATLAS and CMS experiments

    CERN Document Server

    Mariotti, Chiara

    2013-01-01

    Searches for a Higgs boson in models beyond the Standard Model at the ATLAS and CMS experiments at the Large Hadron Collider are discussed. No sign of new physics is present in the data collected at 7 and 8 TeV proton center of mass energies. Limits on model parameters are set. Future studies at higher energy are presented.

  20. Higher-order accuracy of multiscale-double bootstrap for testing regions

    OpenAIRE

    Shimodaira, Hidetoshi

    2013-01-01

    We consider hypothesis testing for the null hypothesis being represented as an arbitrary-shaped region in the parameter space. We compute an approximate p-value by counting how many times the null hypothesis holds in bootstrap replicates. This frequency, known as bootstrap probability, is widely used in evolutionary biology, but often reported as biased in the literature. Based on the asymptotic theory of bootstrap confidence intervals, there have been some new attempts for adjusting the bias...

  1. Bootstrap Co-integration Rank Testing: The Effect of Bias-Correcting Parameter Estimates

    OpenAIRE

    Cavaliere, Giuseppe; Taylor, A. M. Robert; Trenkler, Carsten

    2013-01-01

    In this paper we investigate bootstrap-based methods for bias-correcting the first-stage parameter estimates used in some recently developed bootstrap implementations of the co-integration rank tests of Johansen (1996). In order to do so we adapt the framework of Kilian (1998) which estimates the bias in the original parameter estimates using the average bias in the corresponding parameter esti- mates taken across a large number of auxiliary bootstrap replications. A number of possible imp...

  2. Building Confidence Intervals with Block Bootstraps for the Variance Ratio Test of Predictability

    OpenAIRE

    Eduardo José Araújo Lima; Benjamin Miranda Tabak

    2007-01-01

    This paper compares different versions of the multiple variance ratio test based on bootstrap techniques for the construction of empirical distributions. It also analyzes the crucial issue of selecting optimal block sizes when block bootstrap procedures are used, by applying the methods developed by Hall et al. (1995) and by Politis and White (2004). By comparing the results of the different methods using Monte Carlo simulations, we conclude that methodologies using block bootstrap methods pr...

  3. A bootstrap evaluation of the effect of data splitting on financial time series.

    Science.gov (United States)

    LeBaron, B; Weigend, A S

    1998-01-01

    Exposes problems of the commonly used technique of splitting the available data into training, validation, and test sets that are held fixed, warns about drawing too strong conclusions from such static splits, and shows potential pitfalls of ignoring variability across splits. Using a bootstrap or resampling method, we compare the uncertainty in the solution stemming from the data splitting with neural-network specific uncertainties (parameter initialization, choice of number of hidden units, etc.). We present two results on data from the New York Stock Exchange. First, the variation due to different resamplings is significantly larger than the variation due to different network conditions. This result implies that it is important to not over-interpret a model (or an ensemble of models) estimated on one specific split of the data. Second, on each split, the neural-network solution with early stopping is very close to a linear model; no significant nonlinearities are extracted. PMID:18252443

  4. Bayesian Interpretations of Heteroskedastic Consistent Covariance Estimators Using the Informed Bayesian Bootstrap

    OpenAIRE

    Dale Poirier

    2008-01-01

    This paper provides Bayesian rationalizations for White’s heteroskedastic consistent (HC) covariance estimator and various modifications of it. An informed Bayesian bootstrap provides the statistical framework.

  5. ON THE COMPARISON OF BAYESIAN INFORMATION CRITERION AND DRAPER''S INFORMATION CRITERION IN SELECTION OF AN ASYMMETRIC PRICE RELATIONSHIP: BOOTSTRAP SIMULATION RESULTS

    OpenAIRE

    Henry de-Graft Acquah; Joseph Acquah

    2013-01-01

    Alternative formulations of the Bayesian Information Criteria provide a basis for choosing between competing methods for detecting price asymmetry. However, very little is understood about their performance in the asymmetric price transmission modelling framework. In addressing this issue, this paper introduces and applies parametric bootstrap techniques to evaluate the ability of Bayesian Information Criteria (BIC) and Draper's Information Criteria (DIC) in discriminating between alternative...

  6. A Bootstrap Approach to an Affordable Exploration Program

    Science.gov (United States)

    Oeftering, Richard C.

    2011-01-01

    This paper examines the potential to build an affordable sustainable exploration program by adopting an approach that requires investing in technologies that can be used to build a space infrastructure from very modest initial capabilities. Human exploration has had a history of flight programs that have high development and operational costs. Since Apollo, human exploration has had very constrained budgets and they are expected be constrained in the future. Due to their high operations costs it becomes necessary to consider retiring established space facilities in order to move on to the next exploration challenge. This practice may save cost in the near term but it does so by sacrificing part of the program s future architecture. Human exploration also has a history of sacrificing fully functional flight hardware to achieve mission objectives. An affordable exploration program cannot be built when it involves billions of dollars of discarded space flight hardware, instead, the program must emphasize preserving its high value space assets and building a suitable permanent infrastructure. Further this infrastructure must reduce operational and logistics cost. The paper examines the importance of achieving a high level of logistics independence by minimizing resource consumption, minimizing the dependency on external logistics, and maximizing the utility of resources available. The approach involves the development and deployment of a core suite of technologies that have minimum initial needs yet are able expand upon initial capability in an incremental bootstrap fashion. The bootstrap approach incrementally creates an infrastructure that grows and becomes self sustaining and eventually begins producing the energy, products and consumable propellants that support human exploration. The bootstrap technologies involve new methods of delivering and manipulating energy and materials. These technologies will exploit the space environment, minimize dependencies, and

  7. Structured Metametadata Model to Augment Semantic Searching Algorithms in Learning Content Repository

    Directory of Open Access Journals (Sweden)

    Amirah Ismail

    2011-08-01

    Full Text Available This paper discusses on a novel technique for semantic searching and retrieval of information about learning materials. A novel structured metametadata model has been created to provide the foundation for a semantic search engine to extract, match and map queries to retrieve relevant results. Metametadata encapsulate metadata instances by using the properties and attributes provided by ontologies rather than describing learning objects. The use of ontological views assists the pedagogical content of metadata extracted from learning objects by using the control vocabularies as identified from the metametadata taxonomy. The use of metametadata (based on the metametadata taxonomy supported by the ontologies have contributed towards a novel semantic searching mechanism. This research has presented a metametadata model for identifying semantics and describing learning objects in finer-grain detail that allows for intelligent and smart retrieval by automated search and retrieval software.

  8. Remuestreo Bootstrap y Jackknife en confiabilidad: Caso Exponencial y Weibull

    Directory of Open Access Journals (Sweden)

    Javier Ramírez-Montoya

    2016-01-01

    Full Text Available Se comparan los métodos de remuestreo Bootstrap-t y Jackknife delete I y delete II, utilizando los estimadores no paramétricos de Kaplan-Meier y Nelson-Aalen, que se utilizan con frecuencia en la práctica, teniendo en cuenta diferentes porcentajes de censura, tamaños de muestra y tiempos de interés. La comparación se realiza vía simulación, mediante el error cuadrático medio.

  9. Bootstrapped Oblivious Transfer and Secure Two-Party Function Computation

    CERN Document Server

    Wang, Ye

    2009-01-01

    We propose an information theoretic framework for the secure two-party function computation (SFC) problem and introduce the notion of SFC capacity. We study and extend string oblivious transfer (OT) to sample-wise OT. We propose an efficient, perfectly private OT protocol utilizing the binary erasure channel or source. We also propose the bootstrap string OT protocol which provides disjoint (weakened) privacy while achieving a multiplicative increase in rate, thus trading off security for rate. Finally, leveraging our OT protocol, we construct a protocol for SFC and establish a general lower bound on SFC capacity of the binary erasure channel and source.

  10. Bootstrap framework : web-suunnittelun työkaluna

    OpenAIRE

    Peltomäki, Veera

    2014-01-01

    Pienen näytön omaavat mobiililaitteet kasvattavat suosiotaan Internetin selaamisessa. Samaan aikaan modernit pelikonsolit ja SmartTV:t yleistyvät kuluttajien keskuudessa, jolloin Internetiä voi selata suuren näyttötarkkuuden omaavilla laitteilla. Responsiivinen web-suunnittelu vastaa nykypäivän vaatimuksiin, jossa käyttäjät odottavat sivustoilta yhdenmukaista käyttökokemusta, päätelaitteesta riippumatta. Tämä opinnäytetyö käsittelee responsiivisen Bootstrap frameworkin valintaa web-suunni...

  11. Comparing groups randomization and bootstrap methods using R

    CERN Document Server

    Zieffler, Andrew S; Long, Jeffrey D

    2011-01-01

    A hands-on guide to using R to carry out key statistical practices in educational and behavioral sciences research Computing has become an essential part of the day-to-day practice of statistical work, broadening the types of questions that can now be addressed by research scientists applying newly derived data analytic techniques. Comparing Groups: Randomization and Bootstrap Methods Using R emphasizes the direct link between scientific research questions and data analysis. Rather than relying on mathematical calculations, this book focus on conceptual explanations and the use of statistica

  12. The S-matrix Bootstrap II: Two Dimensional Amplitudes

    CERN Document Server

    Paulos, Miguel F; Toledo, Jonathan; van Rees, Balt C; Vieira, Pedro

    2016-01-01

    We consider constraints on the S-matrix of any gapped, Lorentz invariant quantum field theory in 1 + 1 dimensions due to crossing symmetry and unitarity. In this way we establish rigorous bounds on the cubic couplings of a given theory with a fixed mass spectrum. In special cases we identify interesting integrable theories saturating these bounds. Our analytic bounds match precisely with numerical bounds obtained in a companion paper where we consider massive QFT in an AdS box and study boundary correlators using the technology of the conformal bootstrap.

  13. Comparing groups randomization and bootstrap methods using R

    CERN Document Server

    Zieffler, Andrew S; Long, Jeffrey D

    2011-01-01

    A hands-on guide to using R to carry out key statistical practices in educational and behavioral sciences research Computing has become an essential part of the day-to-day practice of statistical work, broadening the types of questions that can now be addressed by research scientists applying newly derived data analytic techniques. Comparing Groups: Randomization and Bootstrap Methods Using R emphasizes the direct link between scientific research questions and data analysis. Rather than relying on mathematical calculations, this book focus on conceptual explanations and

  14. Convergence rates of empirical block length selectors for block bootstrap

    OpenAIRE

    Nordman, Daniel J.; Lahiri, Soumendra N.

    2014-01-01

    We investigate the accuracy of two general non-parametric methods for estimating optimal block lengths for block bootstraps with time series – the first proposed in the seminal paper of Hall, Horowitz and Jing (Biometrika 82 (1995) 561–574) and the second from Lahiri et al. (Stat. Methodol. 4 (2007) 292–321). The relative performances of these general methods have been unknown and, to provide a comparison, we focus on rates of convergence for these block length selectors for the moving block ...

  15. The use of bootstrap methods for analysing health-related quality of life outcomes (particularly the SF-36

    Directory of Open Access Journals (Sweden)

    Campbell Michael J

    2004-12-01

    Full Text Available Abstract Health-Related Quality of Life (HRQoL measures are becoming increasingly used in clinical trials as primary outcome measures. Investigators are now asking statisticians for advice on how to analyse studies that have used HRQoL outcomes. HRQoL outcomes, like the SF-36, are usually measured on an ordinal scale. However, most investigators assume that there exists an underlying continuous latent variable that measures HRQoL, and that the actual measured outcomes (the ordered categories, reflect contiguous intervals along this continuum. The ordinal scaling of HRQoL measures means they tend to generate data that have discrete, bounded and skewed distributions. Thus, standard methods of analysis such as the t-test and linear regression that assume Normality and constant variance may not be appropriate. For this reason, conventional statistical advice would suggest that non-parametric methods be used to analyse HRQoL data. The bootstrap is one such computer intensive non-parametric method for analysing data. We used the bootstrap for hypothesis testing and the estimation of standard errors and confidence intervals for parameters, in four datasets (which illustrate the different aspects of study design. We then compared and contrasted the bootstrap with standard methods of analysing HRQoL outcomes. The standard methods included t-tests, linear regression, summary measures and General Linear Models. Overall, in the datasets we studied, using the SF-36 outcome, bootstrap methods produce results similar to conventional statistical methods. This is likely because the t-test and linear regression are robust to the violations of assumptions that HRQoL data are likely to cause (i.e. non-Normality. While particular to our datasets, these findings are likely to generalise to other HRQoL outcomes, which have discrete, bounded and skewed distributions. Future research with other HRQoL outcome measures, interventions and populations, is required to

  16. The Use of Cuckoo Search in Estimating the Parameters of Software Reliability Growth Models

    OpenAIRE

    AL-Saati, Dr. Najla Akram; Abd-AlKareem, Marwa

    2013-01-01

    This work aims to investigate the reliability of software products as an important attribute of computer programs; it helps to decide the degree of trustworthiness a program has in accomplishing its specific functions. This is done using the Software Reliability Growth Models (SRGMs) through the estimation of their parameters. The parameters are estimated in this work based on the available failure data and with the search techniques of Swarm Intelligence, namely, the Cuckoo Search (CS) due t...

  17. STATISTICAL EPISTASIS NETWORKS REDUCE THE COMPUTATIONAL COMPLEXITY OF SEARCHING THREE-LOCUS GENETIC MODELS

    OpenAIRE

    Hu, Ting; Andrew, Angeline S; KARAGAS, MARGARET R.; Moore, Jason H.

    2013-01-01

    The rapid development of sequencing technologies makes thousands to millions of genetic attributes available for testing associations with various biological traits. Searching this enormous high-dimensional data space imposes a great computational challenge in genome-wide association studies. We introduce a network-based approach to supervise the search for three-locus models of disease susceptibility. Such statistical epistasis networks (SEN) are built using strong pairwise epistatic interac...

  18. The Distribution of Earnings in an Equilibrium Search Model with State-Dependent Offers and Counteroffers

    OpenAIRE

    Fabien Postel-Vinay; Jean-Marc Robin

    2002-01-01

    We construct an equilibrium job search model with on-the-job search in which firms implement optimal-wage strategies under full information in the sense that they leave no rent to their employees and counter the offers received by their employees from competing firms. Productivity dispersion across firms results in wage mobility both within and across firms. Workers may accept wage cuts to move to firms offering higher future wage prospects. Equilibrium productivity dispersion across ex ante ...

  19. Two new data-dependent choices of m when applying the m-out-of-n bootstrap to hypothesis testing

    OpenAIRE

    Allison, James Samuel; Santana, Leonard; Swanepoel, Jan Willem Hendrik

    2011-01-01

    The traditional non-parametric bootstrap (referred to as the n-out-of-n bootstrap) is a widely applicable and powerful tool for statistical inference, but in important situations it can fail. It is well known that by using a bootstrap sample of size m, different from n, the resulting m-out-of-n bootstrap provides a method for rectifying the traditional bootstrap inconsistency. Moreover, recent studies have shown that interesting cases exist where it is better to use the m-out-of-n bootstrap i...

  20. Modeling Strategies: In Search of the Holy Grail.

    Science.gov (United States)

    Bollen, Kenneth A.

    2000-01-01

    Neither the four-step model nor the one-step procedure can actually tell whether the researcher has the right number of factors in structural equation modeling. In fact, for reasons discussed, a simple formulaic approach to the correct specification of models does not yet exist. (SLD)

  1. A 3D Geometry Model Search Engine to Support Learning

    Science.gov (United States)

    Tam, Gary K. L.; Lau, Rynson W. H.; Zhao, Jianmin

    2009-01-01

    Due to the popularity of 3D graphics in animation and games, usage of 3D geometry deformable models increases dramatically. Despite their growing importance, these models are difficult and time consuming to build. A distance learning system for the construction of these models could greatly facilitate students to learn and practice at different…

  2. Model-Independent Global Search for New High-pT Physics at CDF

    CERN Document Server

    Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; Alvarez-Gonzalez, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P H; Bedeschi, F; Bednar, P; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bölla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, Yu A; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrerar, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carrillol, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cerri, A; Cerritop, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenarr, C; Cuevaso, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; De Barbaro, P; De Cecco, S; Deisher, A; De Lentdeckerd, G; Dell'Orso, Mauro; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernández, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; García, J E; Garfinkel, A F; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokarisa, N; Giordani, M; Giromini, P; Giunta, M; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldsteinc, J; Golossanov, A; Gómez, G; Gómez-Ceballos, G; Goncharov, M; Gonzlez, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraesda Costa, J; Gunay-Unalan, Z; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hillc, C S; Hirschbuehl, D; Höcker, A; Hou, S; Houlden, M; Hsu, S C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Koay, S A; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Le Compte, T; Lee, J; Lee, J; Lee, Y J; Leeq, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lu, R S; Lucchesi, D; Lueck, J; Luci, C; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Mäki, T; Maksimovic, P; Malde, S; Malik, S; Manousakisa, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, M; Martinj, V; Martinez-Ballarin, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNultyi, R; Mehta, A; Mehtälä, P; Menzemerk, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moed, S; Moggi, N; Moon, C S; Moore, R; Morello, M; Movilla-Fernández, P A; Mrenna, S; Mülmenstädt, J; Mukherjee, A; Müller, T; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Österberg, K; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S

    2007-01-01

    Data collected in Run II of the Fermilab Tevatron are searched for indications of new electroweak scale physics. Rather than focusing on particular new physics scenarios, CDF data are analyzed for discrepancies with respect to the standard model prediction. A model-independent approach (Vista) considers the gross features of the data, and is sensitive to new large cross section physics. A quasi-model-independent approach (Sleuth) searches for a significant excess of events with large summed transverse momentum, and is particularly sensitive to new electroweak scale physics that appears predominantly in one final state. This global search for new physics in over three hundred exclusive final states in 927 pb^-1 of ppbar collisions at sqrt(s)=1.96 TeV reveals no such significant indication of physics beyond the standard model.

  3. Model-Independent Global Search for New High-pT Physics at CDF

    Energy Technology Data Exchange (ETDEWEB)

    Collaboration, CDF

    2007-12-01

    Data collected in Run II of the Fermilab Tevatron are searched for indications of new electroweak scale physics. Rather than focusing on particular new physics scenarios, CDF data are analyzed for discrepancies with respect to the standard model prediction. A model-independent approach (Vista) considers the gross features of the data, and is sensitive to new large cross section physics. A quasi-model-independent approach (Sleuth) searches for a significant excess of events with large summed transverse momentum, and is particularly sensitive to new electroweak scale physics that appears predominantly in one final state. This global search for new physics in over three hundred exclusive final states in 927 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV reveals no such significant indication of physics beyond the standard model.

  4. Forecasting drought risks for a water supply storage system using bootstrap position analysis

    Science.gov (United States)

    Tasker, Gary; Dunne, Paul

    1997-01-01

    Forecasting the likelihood of drought conditions is an integral part of managing a water supply storage and delivery system. Position analysis uses a large number of possible flow sequences as inputs to a simulation of a water supply storage and delivery system. For a given set of operating rules and water use requirements, water managers can use such a model to forecast the likelihood of specified outcomes such as reservoir levels falling below a specified level or streamflows falling below statutory passing flows a few months ahead conditioned on the current reservoir levels and streamflows. The large number of possible flow sequences are generated using a stochastic streamflow model with a random resampling of innovations. The advantages of this resampling scheme, called bootstrap position analysis, are that it does not rely on the unverifiable assumption of normality and it allows incorporation of long-range weather forecasts into the analysis.

  5. Current drive and sustain experiments with the bootstrap current in JT-60

    International Nuclear Information System (INIS)

    The current drive and sustain experiments with the neoclassical bootstrap current are performed in the JT-60 tokamak. It is shown that up to 80% of total plasma current is driven by the bootstrap current in extremely high βp regime (βp = 3.2) and the current drive product Ip (bootstrap) n-bareRp up to 4.4 x 1019 MAm-2 has been attained with the bootstrap current. The experimental resistive loop voltages are compared with the calculations using the neoclassical resistivity with and without the bootstrap current and the Spitzer resistivity for a wide range of the plasma current (Ip = 0.5 -2 MA) and the poloidal beta (βp = 0.1 - 3.2). The calculated resistive loop voltage is consistent with the neoclassical prediction including the bootstrap current. Current sustain with the bootstrap current is tested by terminating the Ip feedback control during the high power neutral beam heating. An enhancement of the L/R decay time than those expected from the plasma resistivity with measured Te and Zeff has been confirmed experimentally supporting the large non-inductive current in the plasma and is consistent with the neoclassical prediction. A new technique to calculate the bootstrap current in multi-collisionality regime for finite aspect ratio tokamak has bee developed. The neoclassical bootstrap current is calculated directly through the force balance equations between viscous and friction forces according to the Hirshman-Sigmar theory. The bootstrap current driven by the fast ion component is also included. Ballooning stability of the high βp plasma are analyzed using the current profiles including the bootstrap current. The plasma pressure is close to the ballooning limit in high βp discharges. (author)

  6. DEVELOPING AND PROPOSING A CONCEPTUAL MODEL OF THE FLOW EXPERIENCE DURING ONLINE INFORMATION SEARCH

    Directory of Open Access Journals (Sweden)

    Lazoc Alina

    2012-07-01

    Full Text Available Information search is an essential part of the consumer`s decision making process. The online medium offers new opportunities and challenges for information search activities (in and outside the marketing context. We are interested in the way human information experiences and behaviors are affected by this. Very often online games and social web activities are perceived as challenging, engaging and enjoyable, while online information search is far below this evaluation. Our research proposal implies that using the online medium for information search may provoke enjoyable experiences through the flow state, which may in turn positively influence an individual`s exploratory information behavior and encourage his/her pro-active market behavior. The present study sets out to improve the understanding of the online medium`s impact on human`s exploratory behavior. We hypothesize that the inclusion of the online flow experience in our research model will better explain exploratory information search behaviors. A 11-component conceptual framework is proposed to explain the manifestations of flow, its personal and technological determinants and its behavioral consequence in the context of online information search. Our research has the primary purpose to present an integrated online flow model. Its secondary objective is to stimulate extended research in the area of informational behaviors in the digital age. The paper is organized in three sections. In the first section we briefly report the analysis results of the most relevant online flow theory literature and, drawing on it, we are trying to identify variables and relationships among these. In the second part we propose a research model and use prior flow models to specify a range of testable hypothesis. Drawing on the conceptual model developed, the last section of our study presents the final conclusions and proposes further steps in evaluating the model`s validity. Future research directions

  7. Hierarchical heuristic search using a Gaussian mixture model for UAV coverage planning.

    Science.gov (United States)

    Lin, Lanny; Goodrich, Michael A

    2014-12-01

    During unmanned aerial vehicle (UAV) search missions, efficient use of UAV flight time requires flight paths that maximize the probability of finding the desired subject. The probability of detecting the desired subject based on UAV sensor information can vary in different search areas due to environment elements like varying vegetation density or lighting conditions, making it likely that the UAV can only partially detect the subject. This adds another dimension of complexity to the already difficult (NP-Hard) problem of finding an optimal search path. We present a new class of algorithms that account for partial detection in the form of a task difficulty map and produce paths that approximate the payoff of optimal solutions. The algorithms use the mode goodness ratio heuristic that uses a Gaussian mixture model to prioritize search subregions. The algorithms search for effective paths through the parameter space at different levels of resolution. We compare the performance of the new algorithms against two published algorithms (Bourgault's algorithm and LHC-GW-CONV algorithm) in simulated searches with three real search and rescue scenarios, and show that the new algorithms outperform existing algorithms significantly and can yield efficient paths that yield payoffs near the optimal. PMID:24691199

  8. Hierarchical heuristic search using a Gaussian mixture model for UAV coverage planning.

    Science.gov (United States)

    Lin, Lanny; Goodrich, Michael A

    2014-12-01

    During unmanned aerial vehicle (UAV) search missions, efficient use of UAV flight time requires flight paths that maximize the probability of finding the desired subject. The probability of detecting the desired subject based on UAV sensor information can vary in different search areas due to environment elements like varying vegetation density or lighting conditions, making it likely that the UAV can only partially detect the subject. This adds another dimension of complexity to the already difficult (NP-Hard) problem of finding an optimal search path. We present a new class of algorithms that account for partial detection in the form of a task difficulty map and produce paths that approximate the payoff of optimal solutions. The algorithms use the mode goodness ratio heuristic that uses a Gaussian mixture model to prioritize search subregions. The algorithms search for effective paths through the parameter space at different levels of resolution. We compare the performance of the new algorithms against two published algorithms (Bourgault's algorithm and LHC-GW-CONV algorithm) in simulated searches with three real search and rescue scenarios, and show that the new algorithms outperform existing algorithms significantly and can yield efficient paths that yield payoffs near the optimal.

  9. Bootstrapping Q Methodology to Improve the Understanding of Human Perspectives.

    Science.gov (United States)

    Zabala, Aiora; Pascual, Unai

    2016-01-01

    Q is a semi-qualitative methodology to identify typologies of perspectives. It is appropriate to address questions concerning diverse viewpoints, plurality of discourses, or participation processes across disciplines. Perspectives are interpreted based on rankings of a set of statements. These rankings are analysed using multivariate data reduction techniques in order to find similarities between respondents. Discussing the analytical process and looking for progress in Q methodology is becoming increasingly relevant. While its use is growing in social, health and environmental studies, the analytical process has received little attention in the last decades and it has not benefited from recent statistical and computational advances. Specifically, the standard procedure provides overall and arguably simplistic variability measures for perspectives and none of these measures are associated to individual statements, on which the interpretation is based. This paper presents an innovative approach of bootstrapping Q to obtain additional and more detailed measures of variability, which helps researchers understand better their data and the perspectives therein. This approach provides measures of variability that are specific to each statement and perspective, and additional measures that indicate the degree of certainty with which each respondent relates to each perspective. This supplementary information may add or subtract strength to particular arguments used to describe the perspectives. We illustrate and show the usefulness of this approach with an empirical example. The paper provides full details for other researchers to implement the bootstrap in Q studies with any data collection design.

  10. Assessing Uncertainty in LULC Classification Accuracy by Using Bootstrap Resampling

    Directory of Open Access Journals (Sweden)

    Lin-Hsuan Hsiao

    2016-08-01

    Full Text Available Supervised land-use/land-cover (LULC classifications are typically conducted using class assignment rules derived from a set of multiclass training samples. Consequently, classification accuracy varies with the training data set and is thus associated with uncertainty. In this study, we propose a bootstrap resampling and reclassification approach that can be applied for assessing not only the uncertainty in classification results of the bootstrap-training data sets, but also the classification uncertainty of individual pixels in the study area. Two measures of pixel-specific classification uncertainty, namely the maximum class probability and Shannon entropy, were derived from the class probability vector of individual pixels and used for the identification of unclassified pixels. Unclassified pixels that are identified using the traditional chi-square threshold technique represent outliers of individual LULC classes, but they are not necessarily associated with higher classification uncertainty. By contrast, unclassified pixels identified using the equal-likelihood technique are associated with higher classification uncertainty and they mostly occur on or near the borders of different land-cover.

  11. An empirical equilibrium job search model with continuously distributed heterogeneity of workers' opportunity costs of employment and firms productivities, and search on the job

    OpenAIRE

    Robin, Jean-Marc; Berg, van den, T.J.T.P.; BONTEMPS, Christian

    1998-01-01

    In this paper we present and estimate a synthesis of previous equilibrium search models: allowing for continuous distributions of workers opportunity costs of employment, as well as firms’ productivities. The model allows for on-the-job search, and we assume that job offer arrival rates for workers are independent of their labor market state. We derive the theoretical implications of these assumptions, we provide simulations, and we develop a semi-parametric estimation procedure that we apply...

  12. Literature search for offsite data to improve the DWPF melter off-gas model

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, W.E.

    2000-05-04

    This report documents the literature search performed and any relevant data that may help relax some of the constraints on the DWPF melter off-gas model. The objective of this task was to look for outside sources of technical data to help reduce some of the conservatism built in the DWPF melter off-gas model.

  13. Domain model enhanced search - A comparison of taxonomy, thesaurus and ontology

    NARCIS (Netherlands)

    Schwarz, K.

    2005-01-01

    This thesis investigates the use of domain models for improving electronic search in the context of an enterprise. Specifically the three domain modeling schemes taxonomy, thesaurus and ontology are compared. The result is intended to support information architects in the decision making process to

  14. EXPERIMENTAL HEMORRHAGIC STROKE: SEARCH FOR A BETTER MODEL

    OpenAIRE

    Yabluchanskiy, Andriy; Sawle, Philip; Homer-Vanniasinkam, Shervanthi; Green, Colin; Motterlini, Roberto

    2010-01-01

    Hemorrhagic stroke is one of the least studied problems in the modern neurology. Development of the treatment leads to examination of the pathophysiology of the process, which mainly can be performed in animal models. Recent years few animal model of the hemorrhagic stroke have been proposed. In this review we discuss the differences and benefits of the existing models in the compliance with the process that take place in human patients with hemorrhagic stroke.

  15. Student Search Behaviour in an Online Public Access Catalogue: An Examination of "Searching Mental Models" and "Searcher Self-Concept"

    Science.gov (United States)

    Willson, Rebekah; Given, Lisa M.

    2014-01-01

    Introduction: This paper presents a qualitative exploration of university students' experience of searching an online public access catalogue. The study investigated how students conceptualise their searching process, as well as how students understand themselves as seekers of information. Method: Following a search task, thirty-eight…

  16. An Operational Search and Rescue Model for the Norwegian Sea and the North Sea

    CERN Document Server

    Breivik, Øyvind; 10.1016/j.jmarsys.2007.02.010

    2011-01-01

    A new operational, ensemble-based search and rescue model for the Norwegian Sea and the North Sea is presented. The stochastic trajectory model computes the net motion of a range of search and rescue objects. A new, robust formulation for the relation between the wind and the motion of the drifting object (termed the leeway of the object) is employed. Empirically derived coefficients for 63 categories of search objects compiled by the US Coast Guard are ingested to estimate the leeway of the drifting objects. A Monte Carlo technique is employed to generate an ensemble that accounts for the uncertainties in forcing fields (wind and current), leeway drift properties, and the initial position of the search object. The ensemble yields an estimate of the time-evolving probability density function of the location of the search object, and its envelope defines the search area. Forcing fields from the operational oceanic and atmospheric forecast system of The Norwegian Meteorological Institute are used as input to th...

  17. Data-driven Model-independent Searches for Long-lived Particles at the LHC

    CERN Document Server

    Coccaro, Andrea; Lubatti, H J; Russell, Heather; Shelton, Jessie

    2016-01-01

    Neutral long-lived particles (LLPs) are highly motivated by many BSM scenarios, such as theories of supersymmetry, baryogenesis, and neutral naturalness, and present both tremendous discovery opportunities and experimental challenges for the LHC. A major bottleneck for current LLP searches is the prediction of SM backgrounds, which are often impossible to simulate accurately. In this paper, we propose a general strategy for obtaining differential, data-driven background estimates in LLP searches, thereby notably extending the range of LLP masses and lifetimes that can be discovered at the LHC. We focus on LLPs decaying in the ATLAS Muon System, where triggers providing both signal and control samples are available at the LHC Run-2. While many existing searches require two displaced decays, a detailed knowledge of backgrounds will allow for very inclusive searches that require just one detected LLP decay. As we demonstrate for the $h \\to X X$ signal model of LLP pair production in exotic Higgs decays, this res...

  18. POLYNOMIAL MODEL BASED FAST FRACTIONAL PIXEL SEARCH ALGORITHM FOR H.264/AVC

    Institute of Scientific and Technical Information of China (English)

    Xi Yinglai; Hao Chongyang; Lai Changcai

    2006-01-01

    This paper proposed a novel fast fractional pixel search algorithm based on polynomial model.With the analysis of distribution characteristics of motion compensation error surface inside fractional pixel searching window, the matching error is fitted with parabola along horizontal and vertical direction respectively. The proposed searching strategy needs to check only 6 points rather than 16 or 24 points, which are used in the Hierarchical Fractional Pel Search algorithm (HFPS) for 1/4-pel and 1/8-pel Motion Estimation (ME). The experimental results show that the proposed algorithm shows very good capability in keeping the rate distortion performance while reduces computation load to a large extent compared with HFPS algorithm.

  19. Search for doubly-heavy dibaryons in a quark model

    CERN Document Server

    Vijande, J; Richard, J -M; Sorba, P

    2016-01-01

    We study the stability of hexaquark systems containing two heavy quarks and four light quarks within a simple quark model. No bound or metastable state is found. The reason stems on a delicate interplay between chromoelectric and chromomagnetic effects. Our calculation provides also information about anticharmed pentaquarks that are seemingly unbound in simple quark models.

  20. Searching for turbulence models by artificial neural network

    CERN Document Server

    Gamahara, Masataka

    2016-01-01

    Artificial neural network (ANN) is tested as a tool for finding a new subgrid model of the subgrid-scale (SGS) stress in large-eddy simulation. ANN is used to establish a functional relation between the grid-scale (GS) flow field and the SGS stress without any assumption of the form of function. Data required for training and test of ANN are provided by direct numerical simulation (DNS) of a turbulent channel flow. It is shown that ANN can establish a model similar to the gradient model. The correlation coefficients between the real SGS stress and the output of ANN are comparable to or larger than similarity models, but smaller than a two-parameter dynamic mixed model.

  1. A quasi-model-independent search for new high p{_}T physics at DO

    Energy Technology Data Exchange (ETDEWEB)

    Knuteson, Bruce O.

    2000-12-11

    We present a new quasi-model-independent strategy (''Sleuth'') for searching for physics beyond the standard model. We define final states to be studied, and construct a rule that identifies a set of relevant variables for any particular final state. A novel algorithm searches for regions of excess in those variables and quantifies the significance of any detected excess. This strategy is applied to search for new high p{_}T physics in approximately 100 pb{sup -1} of proton-anti-proton collisions at sqrt(s) = 1.8 TeV collected by the D0 experiment during 1992-1996 at the Fermilab Tevatron. We systematically analyze many exclusive final states, and demonstrate sensitivity to a variety of models predicting new phenomena at the electroweak scale. No evidence of new high p{_}T physics is observed.

  2. MEAN SQUARED ERRORS OF BOOTSTRAP VARIANCE ESTIMATORS FOR U-STATISTICS

    OpenAIRE

    Mizuno, Masayuki; Maesono, Yoshihiko

    2011-01-01

    In this paper, we obtain an asymptotic representation of the bootstrap variance estimator for a class of U-statistics. Using the representation of the estimator, we will obtain a mean squared error of the variance estimator until the order n^. Also we compare the bootstrap and the jackknife variance estimators, theoretically.

  3. A Bootstrap Generalization of Modified Parallel Analysis for IRT Dimensionality Assessment

    Science.gov (United States)

    Finch, Holmes; Monahan, Patrick

    2008-01-01

    This article introduces a bootstrap generalization to the Modified Parallel Analysis (MPA) method of test dimensionality assessment using factor analysis. This methodology, based on the use of Marginal Maximum Likelihood nonlinear factor analysis, provides for the calculation of a test statistic based on a parametric bootstrap using the MPA…

  4. Comparison of Parametric and Nonparametric Bootstrap Methods for Estimating Random Error in Equipercentile Equating

    Science.gov (United States)

    Cui, Zhongmin; Kolen, Michael J.

    2008-01-01

    This article considers two methods of estimating standard errors of equipercentile equating: the parametric bootstrap method and the nonparametric bootstrap method. Using a simulation study, these two methods are compared under three sample sizes (300, 1,000, and 3,000), for two test content areas (the Iowa Tests of Basic Skills Maps and Diagrams…

  5. On the M fewer than N bootstrap approximation to the trimmed mean

    NARCIS (Netherlands)

    Gribkova, N.; Helmers, R.

    2008-01-01

    We show that the M fewer than N (N is the real data sample size, M denotes the size of the bootstrap resample; M=N ! 0, as M ! 1) bootstrap approximation to the distribution of the trimmed mean is consistent without any conditions on the population distribution F, whereas Efron's naive (i.e. M = N)

  6. Bootstrapping to Test for Nonzero Population Correlation Coefficients Using Univariate Sampling

    Science.gov (United States)

    Beasley, William Howard; DeShea, Lise; Toothaker, Larry E.; Mendoza, Jorge L.; Bard, David E.; Rodgers, Joseph Lee

    2007-01-01

    This article proposes 2 new approaches to test a nonzero population correlation ([rho]): the hypothesis-imposed univariate sampling bootstrap (HI) and the observed-imposed univariate sampling bootstrap (OI). The authors simulated correlated populations with various combinations of normal and skewed variates. With [alpha[subscript "set"

  7. Bootstrapping the Small Sample Critical Values of the Rescaled Range Statistic

    OpenAIRE

    Marwan Izzeldin; Anthony Murphy

    2000-01-01

    Finite sample critical values of the rescaled range or R/S statistic may be obtained by bootstrapping. The empirical size and power performance of these critical values is good. Using the post blackened, moving block bootstrap helps to replicate the time dependencies in the original data. The Monte Carlo results show that the asymptotic critical values in Lo (1991) should not be used.

  8. EDGEWORTH EXPANSION AND BOOTSTRAP APPROXIMATION FOR THE STUDENTIZED MLE FROM RANDOMLY CENSORED EXPONENTIAL SAMPLES

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper,the author studies the asymptotic accuracies of the one-term Edgeworth expansions and the bootstrap approximation for the studentized MLE from randomly censored exponential population.It is shown that the Edgeworth expansions and the bootstrap approximation are asymptotically close to the exact distribution of the studentized MLE with a rate.

  9. A Primer on Bootstrap Factor Analysis as Applied to Health Studies Research

    Science.gov (United States)

    Lu, Wenhua; Miao, Jingang; McKyer, E. Lisako J.

    2014-01-01

    Objectives: To demonstrate how the bootstrap method could be conducted in exploratory factor analysis (EFA) with a syntax written in SPSS. Methods: The data obtained from the Texas Childhood Obesity Prevention Policy Evaluation project (T-COPPE project) were used for illustration. A 5-step procedure to conduct bootstrap factor analysis (BFA) was…

  10. Search for Higgs bosons beyond the Standard Model

    Directory of Open Access Journals (Sweden)

    Mankel Rainer

    2015-01-01

    Full Text Available While the existence of a Higgs boson with a mass near 125 GeV has been clearly established, the detailed structure of the entire Higgs sector is yet unclear. Beyond the standard model interpretation, various scenarios for extended Higgs sectors are being considered. Such options include the minimal and next-to-minimal supersymmetric extensions (MSSM and NMSSM of the standard model, more generic Two-Higgs Doublet models (2HDM, as well as truly exotic Higgs bosons decaying e.g. into totally invisible final states. This article presents recent results from the CMS experiment.

  11. Search for the standard model Higgs boson in $l\

    Energy Technology Data Exchange (ETDEWEB)

    Li, Dikai [Pierre and Marie Curie Univ., Paris (France)

    2013-01-01

    Humans have always attempted to understand the mystery of Nature, and more recently physicists have established theories to describe the observed phenomena. The most recent theory is a gauge quantum field theory framework, called Standard Model (SM), which proposes a model comprised of elementary matter particles and interaction particles which are fundamental force carriers in the most unified way. The Standard Model contains the internal symmetries of the unitary product group SU(3)c ⓍSU(2)L Ⓧ U(1)Y , describes the electromagnetic, weak and strong interactions; the model also describes how quarks interact with each other through all of these three interactions, how leptons interact with each other through electromagnetic and weak forces, and how force carriers mediate the fundamental interactions.

  12. articles: Target search of burglars: A revised economic model

    OpenAIRE

    Yochanan Shachmurove; George F. Rengert; Simon Hakim

    2001-01-01

    This article investigates home attributes that attract residential burglars in choosing a target. These attributes are the location of the home, its physical appearance, demographic characteristics of the residents, and the security precautions present. The theoretical foundation of the empirical model is the criminal utility maximization behavior that considers costs and benefits as formulated by Becker. However, this article introduces to the model the spatial dimension of the burglar's sea...

  13. Searching for the Holy Grail of Care Delivery Models.

    Science.gov (United States)

    Mensik, Jennifer

    2016-01-01

    Too often health care executives state the need for more research, knowledge, and information in staffing. Perhaps what we really need is education and support for innovation in operations. In looking for the holy grail of staffing solutions, focused attention will need to be placed on creating innovative care delivery models. Leaders who are tasked with developing innovative care delivery models must have a supportive environment and given time to be successful. PMID:27265951

  14. Financial equalisation in Ukraine: search for an efficient model

    OpenAIRE

    Volokhova Iryna S.

    2013-01-01

    The goal of the article lies in development of an efficient model of financial equalisation of income of territorial budgets, which would allow achievement of the maximum degree of accounting of needs of the population. The author considers advantages and shortcomings of various types of inter-budget transfers and shows the problems of financial equalisation in Ukraine. In the result of the study the article develops an economically more efficient model of financial equalisation for Ukraine, ...

  15. Mechanization in Ghana: Searching for sustainable service supply models:

    OpenAIRE

    DIAO, Xinshen; Cossar, Frances; Houssou, Nazaire; Kolavalli, Shashidhara; Jimah, Kipo; Aboagye, Patrick

    2012-01-01

    This paper assesses the sustainability of the current supply network for mechanization, given government policy. Stylized models of mechanization supply are developed based on experience in Bangladesh, China, and India during similar stages of agricultural transformation. Ghana’s supply network is then analyzed in light of key lessons from the Asian experience. The analysis focuses on two policy issues: (1) whether the current model promoted by the government has left enough room for the pr...

  16. Enterprise Architecture Model that Enables to Search for Patterns of Statistical Information

    Directory of Open Access Journals (Sweden)

    Oleg Chertov

    2013-06-01

    Full Text Available Enterprise architecture is the stem from which developing of any departmental information system should grow and around which it should revolve. In the paper, a fragment of an enterprise architecture model is built using ArchiMate language. This fragment enables to search for information in enterprises which do not work in productive industry. Such enterprises include official statistics. The proposed model embraces all three architectural levels of corresponding information systems, namely, OLTP, OLAP, and Data Mining. Particularly, the latter level enables to search for patterns of statistical information.

  17. Search for Exotic Physics Beyond the Standard Model with the ATLAS Detector

    CERN Document Server

    Smirnov, Yury; The ATLAS collaboration

    2015-01-01

    A summary is given of non-SUSY searches for New Physics with the ATLAS detector at the LHC. Shown results use a data sample collected with a center-of-mass energy of ${\\sqrt{s}=8}$ TeV and an integrated luminosity of around $20$ fb$^{-1}$ in proton-proton collisions. Four recent searches using leptons, photons, missing transverse energy, and jets are presented. No significant deviations from Standard Model expectations are observed, hence new limits on a wide set of predictions for several Standard Model extensions are set.

  18. Fitting statistical distributions the generalized lambda distribution and generalized bootstrap methods

    CERN Document Server

    Karian, Zaven A

    2000-01-01

    Throughout the physical and social sciences, researchers face the challenge of fitting statistical distributions to their data. Although the study of statistical modelling has made great strides in recent years, the number and variety of distributions to choose from-all with their own formulas, tables, diagrams, and general properties-continue to create problems. For a specific application, which of the dozens of distributions should one use? What if none of them fit well?Fitting Statistical Distributions helps answer those questions. Focusing on techniques used successfully across many fields, the authors present all of the relevant results related to the Generalized Lambda Distribution (GLD), the Generalized Bootstrap (GB), and Monte Carlo simulation (MC). They provide the tables, algorithms, and computer programs needed for fitting continuous probability distributions to data in a wide variety of circumstances-covering bivariate as well as univariate distributions, and including situations where moments do...

  19. Application of Search Algorithms for Model Based Regression Testing

    Directory of Open Access Journals (Sweden)

    Sidra Noureen

    2014-04-01

    Full Text Available UML models have gained their significance as reported in the literature. The use of a model to describe the behavior of a system is a proven and major advantage to test. With the help of Model Based Testing (MBT, it is possible to automatically generate test cases. When MBT is applied on large industrial systems, there is problem to sampling the test cases from the suit of entire test because it is difficult to execute the huge number of test cases being generated. The motivation of this study is to design a multi objective genetic algorithm based test case selection technique which can select the most appropriate subset of test cases. NSGA (Non-dominated Sorting Genetic Algorithm is used as an optimization algorithm and its fitness function is improved for selecting test cases from the dataset. It is concluded that there is a room to improve the performance of NSGA algorithm by means of tailoring its respective fitness function.

  20. Searches for superparticles of CMSSM model at the LHC

    International Nuclear Information System (INIS)

    Using the discovery of a SM-like Higgs boson by ATLAS and CMS Collaborations and the observation by CMS and LHCb of BR(Bs ->μ+μ-) decay as well as 8 TeV ATLAS 20 fb-1 jets + ET data set we received an indirect constraint on SUSY model parameters. Considering the constrained versions of the minimal supersymmetric extension of the Standard Model (CMSSM) we used SOFTSUSY and PROSPINO computer programs for calculations of masses and production cross sections of the superparticles, that could be discovered at the LHC.