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Sample records for hurdle negative binomial

  1. Censored Hurdle Negative Binomial Regression (Case Study: Neonatorum Tetanus Case in Indonesia)

    Science.gov (United States)

    Yuli Rusdiana, Riza; Zain, Ismaini; Wulan Purnami, Santi

    2017-06-01

    Hurdle negative binomial model regression is a method that can be used for discreate dependent variable, excess zero and under- and overdispersion. It uses two parts approach. The first part estimates zero elements from dependent variable is zero hurdle model and the second part estimates not zero elements (non-negative integer) from dependent variable is called truncated negative binomial models. The discrete dependent variable in such cases is censored for some values. The type of censor that will be studied in this research is right censored. This study aims to obtain the parameter estimator hurdle negative binomial regression for right censored dependent variable. In the assessment of parameter estimation methods used Maximum Likelihood Estimator (MLE). Hurdle negative binomial model regression for right censored dependent variable is applied on the number of neonatorum tetanus cases in Indonesia. The type data is count data which contains zero values in some observations and other variety value. This study also aims to obtain the parameter estimator and test statistic censored hurdle negative binomial model. Based on the regression results, the factors that influence neonatorum tetanus case in Indonesia is the percentage of baby health care coverage and neonatal visits.

  2. Distinguishing between Binomial, Hypergeometric and Negative Binomial Distributions

    Science.gov (United States)

    Wroughton, Jacqueline; Cole, Tarah

    2013-01-01

    Recognizing the differences between three discrete distributions (Binomial, Hypergeometric and Negative Binomial) can be challenging for students. We present an activity designed to help students differentiate among these distributions. In addition, we present assessment results in the form of pre- and post-tests that were designed to assess the…

  3. A new bivariate negative binomial regression model

    Science.gov (United States)

    Faroughi, Pouya; Ismail, Noriszura

    2014-12-01

    This paper introduces a new form of bivariate negative binomial (BNB-1) regression which can be fitted to bivariate and correlated count data with covariates. The BNB regression discussed in this study can be fitted to bivariate and overdispersed count data with positive, zero or negative correlations. The joint p.m.f. of the BNB1 distribution is derived from the product of two negative binomial marginals with a multiplicative factor parameter. Several testing methods were used to check overdispersion and goodness-of-fit of the model. Application of BNB-1 regression is illustrated on Malaysian motor insurance dataset. The results indicated that BNB-1 regression has better fit than bivariate Poisson and BNB-2 models with regards to Akaike information criterion.

  4. Compound negative binomial distribution with negative multinomial summands

    Science.gov (United States)

    Jordanova, Pavlina K.; Petkova, Monika P.; Stehlík, Milan

    2016-12-01

    The class of Negative Binomial distributions seems to be introduced by Greenwood and Yule in 1920. Due to its wide spread application, investigations of distributions, closely related with it will be always contemporary. Bates, Neyman and Wishart introduce Negative Multinomial distribution. They reach it considering the mixture of independent Poisson distributed random variables with one and the same Gamma mixing variable. This paper investigates a particular case of multivariate compound distribution with one and the same compounding variable. In our case it is Negative Binomial or Sifted Negative Binomial. The summands with equal indexes in different coordinates are Negative Multinomially distributed. In case without shifting, considered as a mixture, the resulting distribution coincides with Mixed Negative Multinomial distribution with scale changed Negative Binomially distributed first parameter. We prove prove that it is Multivariate Power Series Distributed and find explicit form of its parameters. When the summands are geometrically distributed this distribution is stochastically equivalent to a product of independent Bernoulli random variable and appropriate multivariate Geometrically distributed random vector. We show that Compound Shifted Negative Binomial Distribution with Geometric Summands is a particular case of Negative Multinomial distribution with new parameters.

  5. Simulation on Poisson and negative binomial models of count road accident modeling

    Science.gov (United States)

    Sapuan, M. S.; Razali, A. M.; Zamzuri, Z. H.; Ibrahim, K.

    2016-11-01

    Accident count data have often been shown to have overdispersion. On the other hand, the data might contain zero count (excess zeros). The simulation study was conducted to create a scenarios which an accident happen in T-junction with the assumption the dependent variables of generated data follows certain distribution namely Poisson and negative binomial distribution with different sample size of n=30 to n=500. The study objective was accomplished by fitting Poisson regression, negative binomial regression and Hurdle negative binomial model to the simulated data. The model validation was compared and the simulation result shows for each different sample size, not all model fit the data nicely even though the data generated from its own distribution especially when the sample size is larger. Furthermore, the larger sample size indicates that more zeros accident count in the dataset.

  6. Negative Binomial-Lindley Distribution and Its Application

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    Hossein Zamani

    2010-01-01

    Full Text Available Problem statement: The modeling of claims count is one of the most important topics in actuarial theory and practice. Many attempts were implemented in expanding the classes of mixed and compound distributions, especially in the distribution of exponential family, resulting in a better fit on count data. In some cases, it is proven that mixed distributions, in particular mixed Poisson and mixed negative binomial, provided better fit compared to other distributions. Approach: In this study, we introduce a new mixed negative binomial distribution by mixing the distributions of negative binomial (r,p and Lindley (θ, where the reparameterization of p = exp(-λ is considered. Results: The closed form and the factorial moment of the new distribution, i.e., the negative binomial-Lindley distribution, are derived. In addition, the parameters estimation for negative binomial-Lindley via the method of moments (MME and the Maximum Likelihood Estimation (MLE are provided. Conclusion: The application of negative binomial-Lindley distribution is carried out on two samples of insurance data. Based on the results, it is shown that the negative binomial-Lindley provides a better fit compared to the Poisson and the negative binomial for count data where the probability at zero has a large value.

  7. Wigner Function of Density Operator for Negative Binomial Distribution

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    HE Min-Hua; XU Xing-Lei; ZHANG Duan-Ming; LI Hong-Qi; PAN Gui-Jun; YIN Yan-Ping; CHEN Zhi-Yuan

    2008-01-01

    By using the technique of integration within an ordered product (IWOP) of operator we derive Wigner function of density operator for negative binomial distribution of radiation field in the mixed state case, then we derive the Wigner function of squeezed number state, which yields negative binomial distribution by virtue of the entangled state representation and the entangled Wigner operator.

  8. Information-estimation relationships over binomial, negative binomial and Poisson models

    OpenAIRE

    Gil Taborda, Camilo

    2014-01-01

    Mención Internacional en el título de doctor This thesis presents several relationships between information theory and estimation theory over random transformations that are governed through probability mass functions of the type binomial, negative binomial and Poisson. The pioneer expressions that arose relating these fields date back to the 60's when Duncan proved that the input-output mutual information of a channel affected by Gaussian noise can be expressed as a time integral of the c...

  9. Sample size calculation for comparing two negative binomial rates.

    Science.gov (United States)

    Zhu, Haiyuan; Lakkis, Hassan

    2014-02-10

    Negative binomial model has been increasingly used to model the count data in recent clinical trials. It is frequently chosen over Poisson model in cases of overdispersed count data that are commonly seen in clinical trials. One of the challenges of applying negative binomial model in clinical trial design is the sample size estimation. In practice, simulation methods have been frequently used for sample size estimation. In this paper, an explicit formula is developed to calculate sample size based on the negative binomial model. Depending on different approaches to estimate the variance under null hypothesis, three variations of the sample size formula are proposed and discussed. Important characteristics of the formula include its accuracy and its ability to explicitly incorporate dispersion parameter and exposure time. The performance of the formula with each variation is assessed using simulations.

  10. Estimating negative binomial parameters from occurrence data with detection times.

    Science.gov (United States)

    Hwang, Wen-Han; Huggins, Richard; Stoklosa, Jakub

    2016-11-01

    The negative binomial distribution is a common model for the analysis of count data in biology and ecology. In many applications, we may not observe the complete frequency count in a quadrat but only that a species occurred in the quadrat. If only occurrence data are available then the two parameters of the negative binomial distribution, the aggregation index and the mean, are not identifiable. This can be overcome by data augmentation or through modeling the dependence between quadrat occupancies. Here, we propose to record the (first) detection time while collecting occurrence data in a quadrat. We show that under what we call proportionate sampling, where the time to survey a region is proportional to the area of the region, that both negative binomial parameters are estimable. When the mean parameter is larger than two, our proposed approach is more efficient than the data augmentation method developed by Solow and Smith (, Am. Nat. 176, 96-98), and in general is cheaper to conduct. We also investigate the effect of misidentification when collecting negative binomially distributed data, and conclude that, in general, the effect can be simply adjusted for provided that the mean and variance of misidentification probabilities are known. The results are demonstrated in a simulation study and illustrated in several real examples.

  11. Dose-time-response modeling using negative binomial distribution.

    Science.gov (United States)

    Roy, Munmun; Choudhury, Kanak; Islam, M M; Matin, M A

    2013-01-01

    People exposed to certain diseases are required to be treated with a safe and effective dose level of a drug. In epidemiological studies to find out an effective dose level, different dose levels are applied to the exposed and a certain number of cures is observed. Negative binomial distribution is considered to fit overdispersed Poisson count data. This study investigates the time effect on the response at different time points as well as at different dose levels. The point estimation and confidence bands for ED(100p)(t) and LT(100p)(d) are formulated in closed form for the proposed dose-time-response model with the negative binomial distribution. Numerical illustrations are carried out in order to check the performance level of the proposed model.

  12. Combinatorial Clustering and the Beta Negative Binomial Process.

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    Broderick, Tamara; Mackey, Lester; Paisley, John; Jordan, Michael I

    2015-02-01

    We develop a Bayesian nonparametric approach to a general family of latent class problems in which individuals can belong simultaneously to multiple classes and where each class can be exhibited multiple times by an individual. We introduce a combinatorial stochastic process known as the negative binomial process ( NBP ) as an infinite-dimensional prior appropriate for such problems. We show that the NBP is conjugate to the beta process, and we characterize the posterior distribution under the beta-negative binomial process ( BNBP) and hierarchical models based on the BNBP (the HBNBP). We study the asymptotic properties of the BNBP and develop a three-parameter extension of the BNBP that exhibits power-law behavior. We derive MCMC algorithms for posterior inference under the HBNBP , and we present experiments using these algorithms in the domains of image segmentation, object recognition, and document analysis.

  13. Statistical Inference for a Class of Multivariate Negative Binomial Distributions

    DEFF Research Database (Denmark)

    Rubak, Ege H.; Møller, Jesper; McCullagh, Peter

    This paper considers statistical inference procedures for a class of models for positively correlated count variables called -permanental random fields, and which can be viewed as a family of multivariate negative binomial distributions. Their appealing probabilistic properties have earlier been...... studied in the literature, while this is the first statistical paper on -permanental random fields. The focus is on maximum likelihood estimation, maximum quasi-likelihood estimation and on maximum composite likelihood estimation based on uni- and bivariate distributions. Furthermore, new results...

  14. A continuous version of the negative binomial distribution

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    Nimai Kumar Chandra

    2013-05-01

    Full Text Available While discretization of continuous distributions have been attempted for many life distributions the reverse has hardly been attempted. The present endeavor is to establish a reverse relationship by offering a continuous counter part of a discrete distribution namely negative binomial distribution. Different properties of this distribution have been established for a special choice of the parametric value covering class properties, ordering and mean residual life.

  15. Statistical inference for a class of multivariate negative binomial distributions

    DEFF Research Database (Denmark)

    Rubak, Ege Holger; Møller, Jesper; McCullagh, Peter

    This paper considers statistical inference procedures for a class of models for positively correlated count variables called α-permanental random fields, and which can be viewed as a family of multivariate negative binomial distributions. Their appealing probabilistic properties have earlier been...... studied in the literature, while this is the first statistical paper on α-permanental randomfields. The focus is on maximum likelihood estimation, maximum quasi-likelihood estimation and on maximum composite likelihood estimation based on uni- and bivariate distributions. Furthermore, new results for α...

  16. The Parameterized Complexity Analysis of Partition Sort for Negative Binomial Distribution Inputs

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    Singh, Niraj Kumar; Chakraborty, Soubhik

    2012-01-01

    The present paper makes a study on Partition sort algorithm for negative binomial inputs. Comparing the results with those for binomial inputs in our previous work, we find that this algorithm is sensitive to parameters of both distributions. But the main effects as well as the interaction effects involving these parameters and the input size are more significant for negative binomial case.

  17. Large Deviation Results for Generalized Compound Negative Binomial Risk Models

    Institute of Scientific and Technical Information of China (English)

    Fan-chao Kong; Chen Shen

    2009-01-01

    In this paper we extend and improve some results of the large deviation for random sums of random variables.Let {Xn;n≥1} be a sequence of non-negative,independent and identically distributed random variables with common heavy-tailed distribution function F and finite mean μ∈R+,{N(n);n≥0} be a sequence of negative binomial distributed random variables with a parameter p ∈(0,1),n≥0,let {M(n);n≥0} be a Poisson process with intensity λ0.Suppose {N(n);n≥0},{Xn;n≥1} and {M(n);n≥0} are mutually results.These results can be applied to certain problems in insurance and finance.

  18. A comparison of several methods for the confidence intervals of negative binomial proportions

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    Thong, Alfred Lim Sheng; Shan, Fam Pei

    2015-12-01

    This study focuses on the comparison of the performances of several approaches in constructing confidence interval of negative binomial proportions (single negative binomial proportion and the difference between two negative binomial proportions). After that, the strengths and weaknesses of the approaches in constructing confidence interval of negative binomial proportions are figured out. Performances of the approaches will be accessed by comparing their coverage probabilities and average lengths of confidence intervals. For the comparison of the performances of the approaches in single negative binomial proportion, Wald confidence interval (WCI-I), Agresti confidence interval (ACI-I), Wilson's Score confidence interval (WSCI-I) and Jeffrey confidence interval (JCI-I) are used. WSCI-I is the better approach for single negative binomial proportion in term of the average length of confidence intervals and average coverage probability. While for the comparison of the performances of the approaches in the difference between two negative binomial proportions, Wald confidence interval (WCI-II), Agresti confidence interval (ACI-II), Newcombe's Score confidence interval (NSCI-II), Jeffrey confidence interval (JCI-II) and Yule confidence interval (YCI-II) are used. Under different situations, a better approach has been discussed and recommended. There will be different approach that performs better for the coverage probability.

  19. Statistical Properties and Algebraic Characteristics of Quantum Superpositions of Negative Binomial States

    Institute of Scientific and Technical Information of China (English)

    WANG XiaoGuang; FU Hong-Chen

    2001-01-01

    We introduce new kinds of states of quantized radiation fields, which are the superpositions of negative binomial states. They exhibit remarkable nonclassical properties and reduce to Schrodinger cat states in a certain limit.The algebras involved in the even and odd negative binomial states turn out to be generally deformed oscillator algebras.It is found that the even and odd negative binomial states satisfy the same eigenvalue equation with the same eigenvalue and they can be viewed as two-photon nonlinear coherent states. Two methods of generating such the states are proposed.``

  20. Reliability of environmental sampling culture results using the negative binomial intraclass correlation coefficient.

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    Aly, Sharif S; Zhao, Jianyang; Li, Ben; Jiang, Jiming

    2014-01-01

    The Intraclass Correlation Coefficient (ICC) is commonly used to estimate the similarity between quantitative measures obtained from different sources. Overdispersed data is traditionally transformed so that linear mixed model (LMM) based ICC can be estimated. A common transformation used is the natural logarithm. The reliability of environmental sampling of fecal slurry on freestall pens has been estimated for Mycobacterium avium subsp. paratuberculosis using the natural logarithm transformed culture results. Recently, the negative binomial ICC was defined based on a generalized linear mixed model for negative binomial distributed data. The current study reports on the negative binomial ICC estimate which includes fixed effects using culture results of environmental samples. Simulations using a wide variety of inputs and negative binomial distribution parameters (r; p) showed better performance of the new negative binomial ICC compared to the ICC based on LMM even when negative binomial data was logarithm, and square root transformed. A second comparison that targeted a wider range of ICC values showed that the mean of estimated ICC closely approximated the true ICC.

  1. Analysis of generalized negative binomial distributions attached to hyperbolic Landau levels

    Energy Technology Data Exchange (ETDEWEB)

    Chhaiba, Hassan, E-mail: chhaiba.hassan@gmail.com [Department of Mathematics, Faculty of Sciences, Ibn Tofail University, P.O. Box 133, Kénitra (Morocco); Demni, Nizar, E-mail: nizar.demni@univ-rennes1.fr [IRMAR, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex (France); Mouayn, Zouhair, E-mail: mouayn@fstbm.ac.ma [Department of Mathematics, Faculty of Sciences and Technics (M’Ghila), Sultan Moulay Slimane, P.O. Box 523, Béni Mellal (Morocco)

    2016-07-15

    To each hyperbolic Landau level of the Poincaré disc is attached a generalized negative binomial distribution. In this paper, we compute the moment generating function of this distribution and supply its atomic decomposition as a perturbation of the negative binomial distribution by a finitely supported measure. Using the Mandel parameter, we also discuss the nonclassical nature of the associated coherent states. Next, we derive a Lévy-Khintchine-type representation of its characteristic function when the latter does not vanish and deduce that it is quasi-infinitely divisible except for the lowest hyperbolic Landau level corresponding to the negative binomial distribution. By considering the total variation of the obtained quasi-Lévy measure, we introduce a new infinitely divisible distribution for which we derive the characteristic function.

  2. Analysis of generalized negative binomial distributions attached to hyperbolic Landau levels

    Science.gov (United States)

    Chhaiba, Hassan; Demni, Nizar; Mouayn, Zouhair

    2016-07-01

    To each hyperbolic Landau level of the Poincaré disc is attached a generalized negative binomial distribution. In this paper, we compute the moment generating function of this distribution and supply its atomic decomposition as a perturbation of the negative binomial distribution by a finitely supported measure. Using the Mandel parameter, we also discuss the nonclassical nature of the associated coherent states. Next, we derive a Lévy-Khintchine-type representation of its characteristic function when the latter does not vanish and deduce that it is quasi-infinitely divisible except for the lowest hyperbolic Landau level corresponding to the negative binomial distribution. By considering the total variation of the obtained quasi-Lévy measure, we introduce a new infinitely divisible distribution for which we derive the characteristic function.

  3. Generalized Poisson distribution: the property of mixture of Poisson and comparison with negative binomial distribution.

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    Joe, Harry; Zhu, Rong

    2005-04-01

    We prove that the generalized Poisson distribution GP(theta, eta) (eta > or = 0) is a mixture of Poisson distributions; this is a new property for a distribution which is the topic of the book by Consul (1989). Because we find that the fits to count data of the generalized Poisson and negative binomial distributions are often similar, to understand their differences, we compare the probability mass functions and skewnesses of the generalized Poisson and negative binomial distributions with the first two moments fixed. They have slight differences in many situations, but their zero-inflated distributions, with masses at zero, means and variances fixed, can differ more. These probabilistic comparisons are helpful in selecting a better fitting distribution for modelling count data with long right tails. Through a real example of count data with large zero fraction, we illustrate how the generalized Poisson and negative binomial distributions as well as their zero-inflated distributions can be discriminated.

  4. Use of a negative binomial distribution to describe the presence of Sphyrion laevigatum in Genypterus blacodes.

    Science.gov (United States)

    Peña-Rehbein, Patricio; De los Ríos-Escalante, Patricio; Castro, Raúl; Navarrete, Carolina

    2013-01-01

    This paper describes the frequency and number of Sphyrion laevigatum in the skin of Genypterus blacodes, an important economic resource in Chile. The analysis of a spatial distribution model indicated that the parasites tended to cluster. Variations in the number of parasites per host could be described by a negative binomial distribution. The maximum number of parasites observed per host was two.

  5. Marginalized zero-inflated negative binomial regression with application to dental caries.

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    Preisser, John S; Das, Kalyan; Long, D Leann; Divaris, Kimon

    2016-05-10

    The zero-inflated negative binomial regression model (ZINB) is often employed in diverse fields such as dentistry, health care utilization, highway safety, and medicine to examine relationships between exposures of interest and overdispersed count outcomes exhibiting many zeros. The regression coefficients of ZINB have latent class interpretations for a susceptible subpopulation at risk for the disease/condition under study with counts generated from a negative binomial distribution and for a non-susceptible subpopulation that provides only zero counts. The ZINB parameters, however, are not well-suited for estimating overall exposure effects, specifically, in quantifying the effect of an explanatory variable in the overall mixture population. In this paper, a marginalized zero-inflated negative binomial regression (MZINB) model for independent responses is proposed to model the population marginal mean count directly, providing straightforward inference for overall exposure effects based on maximum likelihood estimation. Through simulation studies, the finite sample performance of MZINB is compared with marginalized zero-inflated Poisson, Poisson, and negative binomial regression. The MZINB model is applied in the evaluation of a school-based fluoride mouthrinse program on dental caries in 677 children.

  6. Use of a negative binomial distribution to describe the presence of Sphyrion laevigatum in Genypterus blacodes

    Directory of Open Access Journals (Sweden)

    Patricio Peña-Rehbein

    Full Text Available This paper describes the frequency and number of Sphyrion laevigatum in the skin of Genypterus blacodes, an important economic resource in Chile. The analysis of a spatial distribution model indicated that the parasites tended to cluster. Variations in the number of parasites per host could be described by a negative binomial distribution. The maximum number of parasites observed per host was two.

  7. The Negative Binomial Distribution as a Renewal Model for the Recurrence of Large Earthquakes

    Science.gov (United States)

    Tejedor, Alejandro; Gómez, Javier B.; Pacheco, Amalio F.

    2015-01-01

    The negative binomial distribution is presented as the waiting time distribution of a cyclic Markov model. This cycle simulates the seismic cycle in a fault. As an example, this model, which can describe recurrences with aperiodicities between 0 and 0.5, is used to fit the Parkfield, California earthquake series in the San Andreas Fault. The performance of the model in the forecasting is expressed in terms of error diagrams and compared with other recurrence models from literature.

  8. Binomial distribution sample confidence intervals estimation for positive and negative likelihood ratio medical key parameters.

    Science.gov (United States)

    Bolboacă, Sorana; Jäntschi, Lorentz

    2005-01-01

    Likelihood Ratio medical key parameters calculated on categorical results from diagnostic tests are usually express accompanied with their confidence intervals, computed using the normal distribution approximation of binomial distribution. The approximation creates known anomalies,especially for limit cases. In order to improve the quality of estimation, four new methods (called here RPAC, RPAC0, RPAC1, and RPAC2) were developed and compared with the classical method (called here RPWald), using an exact probability calculation algorithm.Computer implementations of the methods use the PHP language. We defined and implemented the functions of the four new methods and the five criterions of confidence interval assessment. The experiments run for samples sizes which vary in 14 - 34 range, 90 - 100 range (0 binomial variables (1 negative likelihood ratios.

  9. Two Different Definitions of Negative Binomial Distributions%负二项分布的两个不同定义

    Institute of Scientific and Technical Information of China (English)

    康殿统

    2014-01-01

    给出了负二项分布的两个不同定义,给出了两类负二项随机变量的期望、方差与矩母函数。从直观上对这两类负二项随机变量做了描述。%Two definitions of the nega tive binomial distributions are introduced. The expectations, variances and moment generating functions for two types of the negative binomial random variables are computed. Intuitive and descriptive explanations are made for the negative binomial random variables.

  10. Power analyses for negative binomial models with application to multiple sclerosis clinical trials.

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    Rettiganti, Mallik; Nagaraja, H N

    2012-01-01

    We use negative binomial (NB) models for the magnetic resonance imaging (MRI)-based brain lesion count data from parallel group (PG) and baseline versus treatment (BVT) trials for relapsing remitting multiple sclerosis (RRMS) patients, and describe the associated likelihood ratio (LR), score, and Wald tests. We perform power analyses and sample size estimation using the simulated percentiles of the exact distribution of the test statistics for the PG and BVT trials. When compared to the corresponding nonparametric test, the LR test results in 30-45% reduction in sample sizes for the PG trials and 25-60% reduction for the BVT trials.

  11. Use of negative binomial distribution to describe the presence of Anisakis in Thyrsites atun.

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    Peña-Rehbein, Patricio; De los Ríos-Escalante, Patricio

    2012-01-01

    Nematodes of the genus Anisakis have marine fishes as intermediate hosts. One of these hosts is Thyrsites atun, an important fishery resource in Chile between 38 and 41° S. This paper describes the frequency and number of Anisakis nematodes in the internal organs of Thyrsites atun. An analysis based on spatial distribution models showed that the parasites tend to be clustered. The variation in the number of parasites per host could be described by the negative binomial distribution. The maximum observed number of parasites was nine parasites per host. The environmental and zoonotic aspects of the study are also discussed.

  12. Predicting expressway crash frequency using a random effect negative binomial model: A case study in China.

    Science.gov (United States)

    Ma, Zhuanglin; Zhang, Honglu; Chien, Steven I-Jy; Wang, Jin; Dong, Chunjiao

    2017-01-01

    To investigate the relationship between crash frequency and potential influence factors, the accident data for events occurring on a 50km long expressway in China, including 567 crash records (2006-2008), were collected and analyzed. Both the fixed-length and the homogeneous longitudinal grade methods were applied to divide the study expressway section into segments. A negative binomial (NB) model and a random effect negative binomial (RENB) model were developed to predict crash frequency. The parameters of both models were determined using the maximum likelihood (ML) method, and the mixed stepwise procedure was applied to examine the significance of explanatory variables. Three explanatory variables, including longitudinal grade, road width, and ratio of longitudinal grade and curve radius (RGR), were found as significantly affecting crash frequency. The marginal effects of significant explanatory variables to the crash frequency were analyzed. The model performance was determined by the relative prediction error and the cumulative standardized residual. The results show that the RENB model outperforms the NB model. It was also found that the model performance with the fixed-length segment method is superior to that with the homogeneous longitudinal grade segment method.

  13. Using the negative binomial distribution to model overdispersion in ecological count data.

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    Lindén, Andreas; Mäntyniemi, Samu

    2011-07-01

    A Poisson process is a commonly used starting point for modeling stochastic variation of ecological count data around a theoretical expectation. However, data typically show more variation than implied by the Poisson distribution. Such overdispersion is often accounted for by using models with different assumptions about how the variance changes with the expectation. The choice of these assumptions can naturally have apparent consequences for statistical inference. We propose a parameterization of the negative binomial distribution, where two overdispersion parameters are introduced to allow for various quadratic mean-variance relationships, including the ones assumed in the most commonly used approaches. Using bird migration as an example, we present hypothetical scenarios on how overdispersion can arise due to sampling, flocking behavior or aggregation, environmental variability, or combinations of these factors. For all considered scenarios, mean-variance relationships can be appropriately described by the negative binomial distribution with two overdispersion parameters. To illustrate, we apply the model to empirical migration data with a high level of overdispersion, gaining clearly different model fits with different assumptions about mean-variance relationships. The proposed framework can be a useful approximation for modeling marginal distributions of independent count data in likelihood-based analyses.

  14. The destructive negative binomial cure rate model with a latent activation scheme.

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    Cancho, Vicente G; Bandyopadhyay, Dipankar; Louzada, Francisco; Yiqi, Bao

    2013-07-01

    A new flexible cure rate survival model is developed where the initial number of competing causes of the event of interest (say lesions or altered cells) follow a compound negative binomial (NB) distribution. This model provides a realistic interpretation of the biological mechanism of the event of interest as it models a destructive process of the initial competing risk factors and records only the damaged portion of the original number of risk factors. Besides, it also accounts for the underlying mechanisms that leads to cure through various latent activation schemes. Our method of estimation exploits maximum likelihood (ML) tools. The methodology is illustrated on a real data set on malignant melanoma, and the finite sample behavior of parameter estimates are explored through simulation studies.

  15. Modeling citrus huanglongbing data using a zero-inflated negative binomial distribution

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    Eudmar Paiva de Almeida

    2016-06-01

    Full Text Available Zero-inflated data from field experiments can be problematic, as these data require the use of specific statistical models during the analysis process. This study utilized the zero-inflated negative binomial (ZINB model with the log- and logistic-link functions to describe the incidence of plants with Huanglongbing (HLB, caused by Candidatus liberibacter spp. in commercial citrus orchards in the Northwestern Parana State, Brazil. Each orchard was evaluated at different times. The ZINB model with random effects in both link functions provided the best fit, as the inclusion of these effects accounted for variations between orchards and the numbers of diseased plants. The results of this model show that older plants exhibit a lower probability of acquiring HLB. The application of insecticides on a calendar basis or during new foliage flushes resulted in a three times larger probability of developing HLB compared with applying insecticides only when the vector was detected.

  16. Goodness-of-fit tests and model diagnostics for negative binomial regression of RNA sequencing data.

    Directory of Open Access Journals (Sweden)

    Gu Mi

    Full Text Available This work is about assessing model adequacy for negative binomial (NB regression, particularly (1 assessing the adequacy of the NB assumption, and (2 assessing the appropriateness of models for NB dispersion parameters. Tools for the first are appropriate for NB regression generally; those for the second are primarily intended for RNA sequencing (RNA-Seq data analysis. The typically small number of biological samples and large number of genes in RNA-Seq analysis motivate us to address the trade-offs between robustness and statistical power using NB regression models. One widely-used power-saving strategy, for example, is to assume some commonalities of NB dispersion parameters across genes via simple models relating them to mean expression rates, and many such models have been proposed. As RNA-Seq analysis is becoming ever more popular, it is appropriate to make more thorough investigations into power and robustness of the resulting methods, and into practical tools for model assessment. In this article, we propose simulation-based statistical tests and diagnostic graphics to address model adequacy. We provide simulated and real data examples to illustrate that our proposed methods are effective for detecting the misspecification of the NB mean-variance relationship as well as judging the adequacy of fit of several NB dispersion models.

  17. Goodness-of-fit tests and model diagnostics for negative binomial regression of RNA sequencing data.

    Science.gov (United States)

    Mi, Gu; Di, Yanming; Schafer, Daniel W

    2015-01-01

    This work is about assessing model adequacy for negative binomial (NB) regression, particularly (1) assessing the adequacy of the NB assumption, and (2) assessing the appropriateness of models for NB dispersion parameters. Tools for the first are appropriate for NB regression generally; those for the second are primarily intended for RNA sequencing (RNA-Seq) data analysis. The typically small number of biological samples and large number of genes in RNA-Seq analysis motivate us to address the trade-offs between robustness and statistical power using NB regression models. One widely-used power-saving strategy, for example, is to assume some commonalities of NB dispersion parameters across genes via simple models relating them to mean expression rates, and many such models have been proposed. As RNA-Seq analysis is becoming ever more popular, it is appropriate to make more thorough investigations into power and robustness of the resulting methods, and into practical tools for model assessment. In this article, we propose simulation-based statistical tests and diagnostic graphics to address model adequacy. We provide simulated and real data examples to illustrate that our proposed methods are effective for detecting the misspecification of the NB mean-variance relationship as well as judging the adequacy of fit of several NB dispersion models.

  18. Forecasting asthma-related hospital admissions in London using negative binomial models.

    Science.gov (United States)

    Soyiri, Ireneous N; Reidpath, Daniel D; Sarran, Christophe

    2013-05-01

    Health forecasting can improve health service provision and individual patient outcomes. Environmental factors are known to impact chronic respiratory conditions such as asthma, but little is known about the extent to which these factors can be used for forecasting. Using weather, air quality and hospital asthma admissions, in London (2005-2006), two related negative binomial models were developed and compared with a naive seasonal model. In the first approach, predictive forecasting models were fitted with 7-day averages of each potential predictor, and then a subsequent multivariable model is constructed. In the second strategy, an exhaustive search of the best fitting models between possible combinations of lags (0-14 days) of all the environmental effects on asthma admission was conducted. Three models were considered: a base model (seasonal effects), contrasted with a 7-day average model and a selected lags model (weather and air quality effects). Season is the best predictor of asthma admissions. The 7-day average and seasonal models were trivial to implement. The selected lags model was computationally intensive, but of no real value over much more easily implemented models. Seasonal factors can predict daily hospital asthma admissions in London, and there is a little evidence that additional weather and air quality information would add to forecast accuracy.

  19. CUSUM chart to monitor autocorrelated counts using Negative Binomial GARMA model.

    Science.gov (United States)

    Albarracin, Orlando Yesid Esparza; Alencar, Airlane Pereira; Lee Ho, Linda

    2017-01-01

    Cumulative sum control charts have been used for health surveillance due to its efficiency to detect soon small shifts in the monitored series. However, these charts may fail when data are autocorrelated. An alternative procedure is to build a control chart based on the residuals after fitting autoregressive moving average models, but these models usually assume Gaussian distribution for the residuals. In practical health surveillance, count series can be modeled by Poisson or Negative Binomial regression, this last to control overdispersion. To include serial correlations, generalized autoregressive moving average models are proposed. The main contribution of the current article is to measure the impact, in terms of average run length on the performance of cumulative sum charts when the serial correlation is neglected in the regression model. Different statistics based on transformations, the deviance residual, and the likelihood ratio are used to build cumulative sum control charts to monitor counts with time varying means, including trend and seasonal effects. The monitoring of the weekly number of hospital admissions due to respiratory diseases for people aged over 65 years in the city São Paulo-Brazil is considered as an illustration of the current method.

  20. Distinguishing between Rural and Urban Road Segment Traffic Safety Based on Zero-Inflated Negative Binomial Regression Models

    OpenAIRE

    Xuedong Yan; Bin Wang; Meiwu An; Cuiping Zhang

    2012-01-01

    In this study, the traffic crash rate, total crash frequency, and injury and fatal crash frequency were taken into consideration for distinguishing between rural and urban road segment safety. The GIS-based crash data during four and half years in Pikes Peak Area, US were applied for the analyses. The comparative statistical results show that the crash rates in rural segments are consistently lower than urban segments. Further, the regression results based on Zero-Inflated Negative Binomial (...

  1. Maximum likelihood estimation of the negative binomial dispersion parameter for highly overdispersed data, with applications to infectious diseases.

    Directory of Open Access Journals (Sweden)

    James O Lloyd-Smith

    Full Text Available BACKGROUND: The negative binomial distribution is used commonly throughout biology as a model for overdispersed count data, with attention focused on the negative binomial dispersion parameter, k. A substantial literature exists on the estimation of k, but most attention has focused on datasets that are not highly overdispersed (i.e., those with k>or=1, and the accuracy of confidence intervals estimated for k is typically not explored. METHODOLOGY: This article presents a simulation study exploring the bias, precision, and confidence interval coverage of maximum-likelihood estimates of k from highly overdispersed distributions. In addition to exploring small-sample bias on negative binomial estimates, the study addresses estimation from datasets influenced by two types of event under-counting, and from disease transmission data subject to selection bias for successful outbreaks. CONCLUSIONS: Results show that maximum likelihood estimates of k can be biased upward by small sample size or under-reporting of zero-class events, but are not biased downward by any of the factors considered. Confidence intervals estimated from the asymptotic sampling variance tend to exhibit coverage below the nominal level, with overestimates of k comprising the great majority of coverage errors. Estimation from outbreak datasets does not increase the bias of k estimates, but can add significant upward bias to estimates of the mean. Because k varies inversely with the degree of overdispersion, these findings show that overestimation of the degree of overdispersion is very rare for these datasets.

  2. The negative binomial-Lindley distribution as a tool for analyzing crash data characterized by a large amount of zeros.

    Science.gov (United States)

    Lord, Dominique; Geedipally, Srinivas Reddy

    2011-09-01

    The modeling of crash count data is a very important topic in highway safety. As documented in the literature, given the characteristics associated with crash data, transportation safety analysts have proposed a significant number of analysis tools, statistical methods and models for analyzing such data. Among the data issues, we find the one related to crash data which have a large amount of zeros and a long or heavy tail. It has been found that using this kind of dataset could lead to erroneous results or conclusions if the wrong statistical tools or methods are used. Thus, the purpose of this paper is to introduce a new distribution, known as the negative binomial-Lindley (NB-L), which has very recently been introduced for analyzing data characterized by a large number of zeros. The NB-L offers the advantage of being able to handle this kind of datasets, while still maintaining similar characteristics as the traditional negative binomial (NB). In other words, the NB-L is a two-parameter distribution and the long-term mean is never equal to zero. To examine this distribution, simulated and observed data were used. The results show that the NB-L can provide a better statistical fit than the traditional NB for datasets that contain a large amount of zeros.

  3. The analysis of incontinence episodes and other count data in patients with overactive bladder by Poisson and negative binomial regression.

    Science.gov (United States)

    Martina, R; Kay, R; van Maanen, R; Ridder, A

    2015-01-01

    Clinical studies in overactive bladder have traditionally used analysis of covariance or nonparametric methods to analyse the number of incontinence episodes and other count data. It is known that if the underlying distributional assumptions of a particular parametric method do not hold, an alternative parametric method may be more efficient than a nonparametric one, which makes no assumptions regarding the underlying distribution of the data. Therefore, there are advantages in using methods based on the Poisson distribution or extensions of that method, which incorporate specific features that provide a modelling framework for count data. One challenge with count data is overdispersion, but methods are available that can account for this through the introduction of random effect terms in the modelling, and it is this modelling framework that leads to the negative binomial distribution. These models can also provide clinicians with a clearer and more appropriate interpretation of treatment effects in terms of rate ratios. In this paper, the previously used parametric and non-parametric approaches are contrasted with those based on Poisson regression and various extensions in trials evaluating solifenacin and mirabegron in patients with overactive bladder. In these applications, negative binomial models are seen to fit the data well.

  4. Sample Size Estimation for Negative Binomial Regression Comparing Rates of Recurrent Events with Unequal Follow-Up Time.

    Science.gov (United States)

    Tang, Yongqiang

    2015-01-01

    A sample size formula is derived for negative binomial regression for the analysis of recurrent events, in which subjects can have unequal follow-up time. We obtain sharp lower and upper bounds on the required size, which is easy to compute. The upper bound is generally only slightly larger than the required size, and hence can be used to approximate the sample size. The lower and upper size bounds can be decomposed into two terms. The first term relies on the mean number of events in each group, and the second term depends on two factors that measure, respectively, the extent of between-subject variability in event rates, and follow-up time. Simulation studies are conducted to assess the performance of the proposed method. An application of our formulae to a multiple sclerosis trial is provided.

  5. Comparison of linear and zero-inflated negative binomial regression models for appraisal of risk factors associated with dental caries

    Directory of Open Access Journals (Sweden)

    Manu Batra

    2016-01-01

    Full Text Available Context: Dental caries among children has been described as a pandemic disease with a multifactorial nature. Various sociodemographic factors and oral hygiene practices are commonly tested for their influence on dental caries. In recent years, a recent statistical model that allows for covariate adjustment has been developed and is commonly referred zero-inflated negative binomial (ZINB models. Aim: To compare the fit of the two models, the conventional linear regression (LR model and ZINB model to assess the risk factors associated with dental caries. Materials and Methods: A cross-sectional survey was conducted on 1138 12-year-old school children in Moradabad Town, Uttar Pradesh during months of February-August 2014. Selected participants were interviewed using a questionnaire. Dental caries was assessed by recording decayed, missing, or filled teeth (DMFT index. Statistical Analysis Used: To assess the risk factor associated with dental caries in children, two approaches have been applied - LR model and ZINB model. Results: The prevalence of caries-free subjects was 24.1%, and mean DMFT was 3.4 ± 1.8. In LR model, all the variables were statistically significant. Whereas in ZINB model, negative binomial part showed place of residence, father′s education level, tooth brushing frequency, and dental visit statistically significant implying that the degree of being caries-free (DMFT = 0 increases for group of children who are living in urban, whose father is university pass out, who brushes twice a day and if have ever visited a dentist. Conclusion: The current study report that the LR model is a poorly fitted model and may lead to spurious conclusions whereas ZINB model has shown better goodness of fit (Akaike information criterion values - LR: 3.94; ZINB: 2.39 and can be preferred if high variance and number of an excess of zeroes are present.

  6. Crossing the hurdle: the determinants of individual scientific performance

    CERN Document Server

    Baccini, Alberto; Cioni, Martina; Pisani, Caterina

    2013-01-01

    An original dataset referring to a medium-sized Italian university is implemented for analyzing the determinants of scientific research production at individual level. Three different indicators, based on the number of publications and/or citations, are considered. Their distributions are highly skewed, displaying an excess of zero-valued observations, thus zero-inflated and hurdle regression models are introduced. Among them, the Hurdle Negative Binomial model exhibits a good fitting and appears to be reasonably coherent with the underlying generating data process. Indeed, the performance of active researchers is described by the count component of the model, while the odds to be in a non-active status is modelled by the zero component. Individual characteristics, teaching and administrative activities, as well as the features of the department the researcher belongs to, are considered as explanatory variables. The analysis of the results highlights that scientific productivity is lower for oldest active res...

  7. The overlooked potential of generalized linear models in astronomy - III. Bayesian negative binomial regression and globular cluster populations

    Science.gov (United States)

    de Souza, R. S.; Hilbe, J. M.; Buelens, B.; Riggs, J. D.; Cameron, E.; Ishida, E. E. O.; Chies-Santos, A. L.; Killedar, M.

    2015-10-01

    In this paper, the third in a series illustrating the power of generalized linear models (GLMs) for the astronomical community, we elucidate the potential of the class of GLMs which handles count data. The size of a galaxy's globular cluster (GC) population (NGC) is a prolonged puzzle in the astronomical literature. It falls in the category of count data analysis, yet it is usually modelled as if it were a continuous response variable. We have developed a Bayesian negative binomial regression model to study the connection between NGC and the following galaxy properties: central black hole mass, dynamical bulge mass, bulge velocity dispersion and absolute visual magnitude. The methodology introduced herein naturally accounts for heteroscedasticity, intrinsic scatter, errors in measurements in both axes (either discrete or continuous) and allows modelling the population of GCs on their natural scale as a non-negative integer variable. Prediction intervals of 99 per cent around the trend for expected NGC comfortably envelope the data, notably including the Milky Way, which has hitherto been considered a problematic outlier. Finally, we demonstrate how random intercept models can incorporate information of each particular galaxy morphological type. Bayesian variable selection methodology allows for automatically identifying galaxy types with different productions of GCs, suggesting that on average S0 galaxies have a GC population 35 per cent smaller than other types with similar brightness.

  8. Factors related to the use of antenatal care services in Ethiopia: Application of the zero-inflated negative binomial model.

    Science.gov (United States)

    Assefa, Enyew; Tadesse, Mekonnen

    2016-08-11

    The major causes for poor health in developing countries are inadequate access and under-use of modern health care services. The objective of this study was to identify and examine factors related to the use of antenatal care services using the 2011 Ethiopia Demographic and Health Survey data. The number of antenatal care visits during the last pregnancy by mothers aged 15 to 49 years (n = 7,737) was analyzed. More than 55% of the mothers did not use antenatal care (ANC) services, while more than 22% of the women used antenatal care services less than four times. More than half of the women (52%) who had access to health services had at least four antenatal care visits. The zero-inflated negative binomial model was found to be more appropriate for analyzing the data. Place of residence, age of mothers, woman's educational level, employment status, mass media exposure, religion, and access to health services were significantly associated with the use of antenatal care services. Accordingly, there should be progress toward a health-education program that enables more women to utilize ANC services, with the program targeting women in rural areas, uneducated women, and mothers with higher birth orders through appropriate media.

  9. Single-gene negative binomial regression models for RNA-Seq data with higher-order asymptotic inference.

    Science.gov (United States)

    Di, Yanming

    2015-01-01

    We consider negative binomial (NB) regression models for RNA-Seq read counts and investigate an approach where such NB regression models are fitted to individual genes separately and, in particular, the NB dispersion parameter is estimated from each gene separately without assuming commonalities between genes. This single-gene approach contrasts with the more widely-used dispersion-modeling approach where the NB dispersion is modeled as a simple function of the mean or other measures of read abundance, and then estimated from a large number of genes combined. We show that through the use of higher-order asymptotic techniques, inferences with correct type I errors can be made about the regression coefficients in a single-gene NB regression model even when the dispersion is unknown and the sample size is small. The motivations for studying single-gene models include: 1) they provide a basis of reference for understanding and quantifying the power-robustness trade-offs of the dispersion-modeling approach; 2) they can also be potentially useful in practice if moderate sample sizes become available and diagnostic tools indicate potential problems with simple models of dispersion.

  10. Analysis of U.S. freight-train derailment severity using zero-truncated negative binomial regression and quantile regression.

    Science.gov (United States)

    Liu, Xiang; Saat, M Rapik; Qin, Xiao; Barkan, Christopher P L

    2013-10-01

    Derailments are the most common type of freight-train accidents in the United States. Derailments cause damage to infrastructure and rolling stock, disrupt services, and may cause casualties and harm the environment. Accordingly, derailment analysis and prevention has long been a high priority in the rail industry and government. Despite the low probability of a train derailment, the potential for severe consequences justify the need to better understand the factors influencing train derailment severity. In this paper, a zero-truncated negative binomial (ZTNB) regression model is developed to estimate the conditional mean of train derailment severity. Recognizing that the mean is not the only statistic describing data distribution, a quantile regression (QR) model is also developed to estimate derailment severity at different quantiles. The two regression models together provide a better understanding of train derailment severity distribution. Results of this work can be used to estimate train derailment severity under various operational conditions and by different accident causes. This research is intended to provide insights regarding development of cost-efficient train safety policies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Linking parasite populations in hosts to parasite populations in space through Taylor's law and the negative binomial distribution.

    Science.gov (United States)

    Cohen, Joel E; Poulin, Robert; Lagrue, Clément

    2017-01-03

    The spatial distribution of individuals of any species is a basic concern of ecology. The spatial distribution of parasites matters to control and conservation of parasites that affect human and nonhuman populations. This paper develops a quantitative theory to predict the spatial distribution of parasites based on the distribution of parasites in hosts and the spatial distribution of hosts. Four models are tested against observations of metazoan hosts and their parasites in littoral zones of four lakes in Otago, New Zealand. These models differ in two dichotomous assumptions, constituting a 2 × 2 theoretical design. One assumption specifies whether the variance function of the number of parasites per host individual is described by Taylor's law (TL) or the negative binomial distribution (NBD). The other assumption specifies whether the numbers of parasite individuals within each host in a square meter of habitat are independent or perfectly correlated among host individuals. We find empirically that the variance-mean relationship of the numbers of parasites per square meter is very well described by TL but is not well described by NBD. Two models that posit perfect correlation of the parasite loads of hosts in a square meter of habitat approximate observations much better than two models that posit independence of parasite loads of hosts in a square meter, regardless of whether the variance-mean relationship of parasites per host individual obeys TL or NBD. We infer that high local interhost correlations in parasite load strongly influence the spatial distribution of parasites. Local hotspots could influence control and conservation of parasites.

  12. Compound Negative Binomial Distribution and Compound Poisson Distribution%复合负二项分布与复合泊松分布

    Institute of Scientific and Technical Information of China (English)

    魏瑛源

    2014-01-01

    运用矩母函数证明了任何一个复合负二项分布可以写成一个复合泊松分布,并给出一个具体实例。%By using the moment generating function , we prove that a compound negative binomial distribution can be expressed as a compound Poisson distribution .An example is shown .

  13. An Approximate Interval Estimate on the Parameter of Negative Binomial Distribution%负二项分布参数的一类近似区间估计

    Institute of Scientific and Technical Information of China (English)

    姜培华

    2012-01-01

    借助负二项分布和卡方分布的极限关系,推导给出当参数P较小条件下的近似区间估计,并通过数值例子介绍了此区间估计方法的应用.%An approximate interval estimate for small was gained with the limit relationship of negative binomi- al distribution and the chi - square distribution ; Finally, the method of interval estimate was studied and illustration was shown by examples.

  14. 负二项分布概率最大值的性质%The Characters of the Probability Maximum Value for Negative Binomial Distribution

    Institute of Scientific and Technical Information of China (English)

    丁勇

    2016-01-01

    The character of probability maximum value for negative binomial distribution was explored. The probability maximum value for negative binomial distribution was a function of p and r, where p was the probability of success for each test, and r was the number of the first successful test. It was a mono-tonically increasing continuous function of p when r was given,only (r-1)/p was a integer, its derivative did not exist, and a monotone decreasing function of r when p was given.%负二项分布概率的最大值是每次试验成功的概率p和首次试验成功次数r的函数。对确定的r,该函数是p的单调上升的连续函数,仅当(r-1)/p是整数时不可导;对确定的p,该函数是r的单调下降函数。

  15. Generalized negative binomial distribution: a promising statistical distribution for Oncomelania hupensis in the lake- and marsh-land regions of China.

    Science.gov (United States)

    Zhang, Z J; Ong, S H; Lynn, H S; Peng, W X; Zhou, Y B; Zhao, G M; Jiang, Q W

    2008-09-01

    A new generalization of the negative binomial distribution (GNBD) is introduced and fitted to counts of Oncomelania hupensis, the intermediate host of Schistosoma japonicum, made, in areas of Chinese lakeland and marshland, early in the winter of 2005 and late in the spring of 2006. The GNBD was found to fit the snail data better than the standard negative binomial distribution (NBD) that has previously been widely used to model the distribution of O. hupensis. With two more parameters than the NBD, the GNBD can integrate many discrete distributions and is more flexible than the NBD in modelling O. hupensis. It also provides a better theoretical distribution for the quantitative study of O. hupensis, especially in building an accurate prediction model of snail density. The justification for adopting the GNBD is discussed. The GNBD allows researchers to broaden the field in the quantitative study not only of O. hupensis and schistosomiasis japonica but also of other environment-related helminthiases and family-clustered diseases that have, traditionally, been modelled using the NBD.

  16. A new Markov Binomial distribution

    OpenAIRE

    Leda D. Minkova; Omey, Edward

    2011-01-01

    In this paper, we introduce a two state homogeneous Markov chain and define a geometric distribution related to this Markov chain. We define also the negative binomial distribution similar to the classical case and call it NB related to interrupted Markov chain. The new binomial distribution is related to the interrupted Markov chain. Some characterization properties of the Geometric distributions are given. Recursion formulas and probability mass functions for the NB distribution and the new...

  17. Two Interval Estimates on the Parameter of Negative Binomial Distribution%负二项分布参数的两种区间估计

    Institute of Scientific and Technical Information of China (English)

    姜培华; 范国良

    2012-01-01

    研究了负二项分布参数的区间估计方法,给出其两种区间估计方法.首先给出负二项分布参数的精确区间估计方法;其次给出大样本近似区间估计方法.最后通过数值例子介绍这些区间估计方法的应用.%The methods of interval estimate on the parameter of negative binomial distribution have been studied. Two methods are given. Firstly, the accurate interval estimate is put forward ; secondly, large sample approximate inter-val estimate is gained; Finally,these methods of interval estimate are studied and illustration is shown by examples.

  18. Properties of Negative Binomial Distribution and Its Applications in the RiskManagement%负二项分布的优良特性及其在风险管理中的应用

    Institute of Scientific and Technical Information of China (English)

    王丙参; 何万生; 戴宁

    2011-01-01

    This article discusses the properties and promotion of the two basic negative binomial distributions,gives closed of conditional probabilities and a non-classical confidence interval estimate under the first negative binomial distribution,discusses the relationship between the second negative binomial distribution to poisson distribution.%研究了负二项分布的两个基本模型及推广,得到第一类负二项分布条件概率具有封闭性且给出参数的一个非经典置信区间估计,特别研究了第二类负二项分布与泊松分布的关系。

  19. Chain binomial models and binomial autoregressive processes.

    Science.gov (United States)

    Weiss, Christian H; Pollett, Philip K

    2012-09-01

    We establish a connection between a class of chain-binomial models of use in ecology and epidemiology and binomial autoregressive (AR) processes. New results are obtained for the latter, including expressions for the lag-conditional distribution and related quantities. We focus on two types of chain-binomial model, extinction-colonization and colonization-extinction models, and present two approaches to parameter estimation. The asymptotic distributions of the resulting estimators are studied, as well as their finite-sample performance, and we give an application to real data. A connection is made with standard AR models, which also has implications for parameter estimation.

  20. Application of a random effects negative binomial model to examine tram-involved crash frequency on route sections in Melbourne, Australia.

    Science.gov (United States)

    Naznin, Farhana; Currie, Graham; Logan, David; Sarvi, Majid

    2016-07-01

    Safety is a key concern in the design, operation and development of light rail systems including trams or streetcars as they impose crash risks on road users in terms of crash frequency and severity. The aim of this study is to identify key traffic, transit and route factors that influence tram-involved crash frequencies along tram route sections in Melbourne. A random effects negative binomial (RENB) regression model was developed to analyze crash frequency data obtained from Yarra Trams, the tram operator in Melbourne. The RENB modelling approach can account for spatial and temporal variations within observation groups in panel count data structures by assuming that group specific effects are randomly distributed across locations. The results identify many significant factors effecting tram-involved crash frequency including tram service frequency (2.71), tram stop spacing (-0.42), tram route section length (0.31), tram signal priority (-0.25), general traffic volume (0.18), tram lane priority (-0.15) and ratio of platform tram stops (-0.09). Findings provide useful insights on route section level tram-involved crashes in an urban tram or streetcar operating environment. The method described represents a useful planning tool for transit agencies hoping to improve safety performance.

  1. Library Book Circulation and the Beta-Binomial Distribution.

    Science.gov (United States)

    Gelman, E.; Sichel, H. S.

    1987-01-01

    Argues that library book circulation is a binomial rather than a Poisson process, and that individual book popularities are continuous beta distributions. Three examples demonstrate the superiority of beta over negative binomial distribution, and it is suggested that a bivariate-binomial process would be helpful in predicting future book…

  2. The Ongoing Binomial Revolution

    CERN Document Server

    Goss, David

    2011-01-01

    The Binomial Theorem has long been essential in mathematics. In one form or another it was known to the ancients and, in the hands of Leibniz, Newton, Euler, Galois, and others, it became an essential tool in both algebra and analysis. Indeed, Newton early on developed certain binomial series (see Section \\ref{newton}) which played a role in his subsequent work on the calculus. From the work of Leibniz, Galois, Frobenius, and many others, we know of its essential role in algebra. In this paper we rapidly trace the history of the Binomial Theorem, binomial series, and binomial coefficients, with emphasis on their decisive role in function field arithmetic. We also explain conversely how function field arithmetic is now leading to new results in the binomial theory via insights into characteristic $p$ $L$-series.

  3. Statistical prop erties of binomial and negative-binomial combinational optical field state and its generation in quantum diffusion channel%二项-负二项组合光场态的光子统计性质及其在量子扩散通道中的生成∗

    Institute of Scientific and Technical Information of China (English)

    范洪义; 吴泽

    2015-01-01

    According to the combinational binomial-negative-binomial distribution, we propose a binomial-negative-binomial combinational optical field state, which can be generated in the process of a Fock state |m⟩⟨m| passing through a quantum-mechanical diffusion channel. We derive the second-order coherence degree formula, g(2) (t)=2− m2+m(m+κt)2 , which is the diffusion constant. We find that in the process of the Fock state undergoing quantum diffusion and becoming classical, the corresponding photon statistics evolves from sub-Poissonian distribution to Poisson distribution and finally goes to a chaotic state. We also find that the more photons in the initial Fock state, the longer time is needed for quantum decoherence.%在组合二项-负二项分布的基础上,提出了二项-负二项组合光场态,这种态能在Fo ck态历经量子扩散通道的过程中实现。导出了此光场的二阶相干度公式, g(2)(t)=2− m2+m(m+κt)2,发现随着时间的推移光场从非经典Fock态变为经典态,光子数m经扩散通道后变成了m+κt,κ是扩散常数,相应的光子统计从亚泊松分布历经泊松分布再变成混沌光;初始Fo ck态的光子数越多,则扩散所需的时间越长。

  4. An empirical tool to evaluate the safety of cyclists: Community based, macro-level collision prediction models using negative binomial regression.

    Science.gov (United States)

    Wei, Feng; Lovegrove, Gordon

    2013-12-01

    Today, North American governments are more willing to consider compact neighborhoods with increased use of sustainable transportation modes. Bicycling, one of the most effective modes for short trips with distances less than 5km is being encouraged. However, as vulnerable road users (VRUs), cyclists are more likely to be injured when involved in collisions. In order to create a safe road environment for them, evaluating cyclists' road safety at a macro level in a proactive way is necessary. In this paper, different generalized linear regression methods for collision prediction model (CPM) development are reviewed and previous studies on micro-level and macro-level bicycle-related CPMs are summarized. On the basis of insights gained in the exploration stage, this paper also reports on efforts to develop negative binomial models for bicycle-auto collisions at a community-based, macro-level. Data came from the Central Okanagan Regional District (CORD), of British Columbia, Canada. The model results revealed two types of statistical associations between collisions and each explanatory variable: (1) An increase in bicycle-auto collisions is associated with an increase in total lane kilometers (TLKM), bicycle lane kilometers (BLKM), bus stops (BS), traffic signals (SIG), intersection density (INTD), and arterial-local intersection percentage (IALP). (2) A decrease in bicycle collisions was found to be associated with an increase in the number of drive commuters (DRIVE), and in the percentage of drive commuters (DRP). These results support our hypothesis that in North America, with its current low levels of bicycle use (macro-level CPMs. Copyright © 2012. Published by Elsevier Ltd.

  5. A semiparametric negative binomial generalized linear model for modeling over-dispersed count data with a heavy tail: Characteristics and applications to crash data.

    Science.gov (United States)

    Shirazi, Mohammadali; Lord, Dominique; Dhavala, Soma Sekhar; Geedipally, Srinivas Reddy

    2016-06-01

    Crash data can often be characterized by over-dispersion, heavy (long) tail and many observations with the value zero. Over the last few years, a small number of researchers have started developing and applying novel and innovative multi-parameter models to analyze such data. These multi-parameter models have been proposed for overcoming the limitations of the traditional negative binomial (NB) model, which cannot handle this kind of data efficiently. The research documented in this paper continues the work related to multi-parameter models. The objective of this paper is to document the development and application of a flexible NB generalized linear model with randomly distributed mixed effects characterized by the Dirichlet process (NB-DP) to model crash data. The objective of the study was accomplished using two datasets. The new model was compared to the NB and the recently introduced model based on the mixture of the NB and Lindley (NB-L) distributions. Overall, the research study shows that the NB-DP model offers a better performance than the NB model once data are over-dispersed and have a heavy tail. The NB-DP performed better than the NB-L when the dataset has a heavy tail, but a smaller percentage of zeros. However, both models performed similarly when the dataset contained a large amount of zeros. In addition to a greater flexibility, the NB-DP provides a clustering by-product that allows the safety analyst to better understand the characteristics of the data, such as the identification of outliers and sources of dispersion.

  6. 零膨胀负二项回归模型的推广与费率厘定%Generalization of zero-inflated negative binomial regression model and ratemaking

    Institute of Scientific and Technical Information of China (English)

    徐昕; 袁卫; 孟生旺

    2012-01-01

    When the claim numbers appear to be over-dispersed in ratemaking, negative binomial regression model will be usually applied. However, it is also possible that the claim numbers may be zero-inflated, and then the negative binomial regression is not suitable for those data. The paper makes generalization of zero-inflated negative binomial distribution based on traditional ones to deal with the over-dispersed and zero-inflated data simultaneously. At the end of the paper, the extended model is applied to a data set of automobile insurance loss and the result shows that the goodness-of-fit can be effectively improved.%在费率厘定中,当索赔次数数据存在过离散(over-dispersion)特征时,通常会采用负二项回归模型,但当索赔数据中同时又出现零膨胀(zero-inflated)问题时,负二项回归模型不再适合对这样的数据进行分析.在传统的零膨胀负二项回归模型为基础,并将其推广到更为一般的形式,同时利用解决费率厘定中出现的既有过离散又有零膨胀的问题.通过对一组汽车损失数据的拟合,推广后的零膨胀负二项回归模型有效地改善了拟合效果.

  7. Crash Frequency Analysis Using Hurdle Models with Random Effects Considering Short-Term Panel Data.

    Science.gov (United States)

    Chen, Feng; Ma, Xiaoxiang; Chen, Suren; Yang, Lin

    2016-10-26

    Random effect panel data hurdle models are established to research the daily crash frequency on a mountainous section of highway I-70 in Colorado. Road Weather Information System (RWIS) real-time traffic and weather and road surface conditions are merged into the models incorporating road characteristics. The random effect hurdle negative binomial (REHNB) model is developed to study the daily crash frequency along with three other competing models. The proposed model considers the serial correlation of observations, the unbalanced panel-data structure, and dominating zeroes. Based on several statistical tests, the REHNB model is identified as the most appropriate one among four candidate models for a typical mountainous highway. The results show that: (1) the presence of over-dispersion in the short-term crash frequency data is due to both excess zeros and unobserved heterogeneity in the crash data; and (2) the REHNB model is suitable for this type of data. Moreover, time-varying variables including weather conditions, road surface conditions and traffic conditions are found to play importation roles in crash frequency. Besides the methodological advancements, the proposed technology bears great potential for engineering applications to develop short-term crash frequency models by utilizing detailed data from field monitoring data such as RWIS, which is becoming more accessible around the world.

  8. 两类零膨胀负二项回归模型在汽车保险定价中的应用%Application of two types of negative binomial regression models in automobile insurance ratemaking

    Institute of Scientific and Technical Information of China (English)

    徐昕; 郭念国

    2011-01-01

    The paper discusses two types of distribution forms zero-inflated negative binomial regression models, and applies the two models to a set of actual automobile insurance loss data. The results show that the two types of zero-inflated negative binomial regression models can improve the goodness-of-fit effectively than the common claim frequency models when the loss data is zero-inflated.%讨论了两种分布形式的零膨胀负二项回归模型,并应用一组实际汽车保险损失数据对两类模型进行了实证比较.结果表明,对于具有零膨胀特征的损失数据,零膨胀负二项回归模型的拟合结果优于普通索赔频率回归模型.

  9. On approximation of Markov binomial distributions

    CERN Document Server

    Xia, Aihua; 10.3150/09-BEJ194

    2010-01-01

    For a Markov chain $\\mathbf{X}=\\{X_i,i=1,2,...,n\\}$ with the state space $\\{0,1\\}$, the random variable $S:=\\sum_{i=1}^nX_i$ is said to follow a Markov binomial distribution. The exact distribution of $S$, denoted $\\mathcal{L}S$, is very computationally intensive for large $n$ (see Gabriel [Biometrika 46 (1959) 454--460] and Bhat and Lal [Adv. in Appl. Probab. 20 (1988) 677--680]) and this paper concerns suitable approximate distributions for $\\mathcal{L}S$ when $\\mathbf{X}$ is stationary. We conclude that the negative binomial and binomial distributions are appropriate approximations for $\\mathcal{L}S$ when $\\operatorname {Var}S$ is greater than and less than $\\mathbb{E}S$, respectively. Also, due to the unique structure of the distribution, we are able to derive explicit error estimates for these approximations.

  10. Requirement of Working Stably of Compound Negative Binomial Risk Model with Constant Interest rate%常利率复合负二项风险模型下稳定经营的必要条件

    Institute of Scientific and Technical Information of China (English)

    乔克林; 高渊; 张宁

    2015-01-01

    Assume that insurance companies began to hold capital to u,with constane δ is accumulation of interest rates,and policy number always obey hegative binomia process,manage compensate total number follows poisson process. we give the compound negative binomial risk model with constant interest rate and the requirement of insur-ance company working stably.%假设保险公司刚开始持有的资本为u,以常数δ为利率积累,并且保单总份数服从负二项过程,理赔总次数服从Poisson过程,给出常利率复合负二项风险模型以及稳定经营的必要条件。

  11. 一类新的损失函数下负二项分布模型的Bayes可靠生分析%The Bayesian Analysis for Negative Binomial Distribution under a New Loss Function

    Institute of Scientific and Technical Information of China (English)

    王琪; 李玮

    2011-01-01

    The Bayesian and hierarchical Bayesian estimators of reliability of negative binomial distribution are obtained, and the E Bayesian estimator is also discussed by E Bayesian approach. Finally, a numberical example is given to compare the former three estmators, and the contusion shows that the E Bayesian estimator is better than the hierarchical Bayesian estimator.%在一类新的加权平方损失函数下,给出了负二项分布可靠度的Bayes和多层Bayes估计,并利用EBayes方法给出了负二项分布可靠度的E Bayes估计.针对得到的3种估计,给出了数值模拟,结果表明:EBayes估计比多层Bayes估计优良.

  12. 负二项分布参数的贝叶斯区间估计问题%Research of the Bayesian Interval Estimate on the Parameter of Negative Binomial Distribution

    Institute of Scientific and Technical Information of China (English)

    姜培华; 纪习习; 吴玲

    2014-01-01

    In terms of prior distribution of Beta distribution, the Bayesian estimation method on the unknown parame-ter θ of negative binomial distribution was studied. By means of the relations between Beta distribution and the F dis-tribution the general posterior interval estimation of parameter θ was given, and the shortest posterior interval estima-tion by means of conditional extreme was gained. By comparing the discussion analysis and numerical examples den-sity curve shape of the different parameters, it was concluded that in the case of small samples, the shortest confi-dence interval estimation method is worth using.%研究了在先验分布为贝塔分布下,负二项分布未知参数θ的贝叶斯区间估计方法。借助Beta分布与F分布的关系给出了参数θ的一般后验区间估计,并给出了参数θ的最短后验区间估计的条件极值解法。通过对参数取值不同的密度曲线形状的讨论分析和数值实例对比,得出结论:在小样本情况下,最短置信区间估计方法值得采用。

  13. The Binomial Distribution in Shooting

    Science.gov (United States)

    Chalikias, Miltiadis S.

    2009-01-01

    The binomial distribution is used to predict the winner of the 49th International Shooting Sport Federation World Championship in double trap shooting held in 2006 in Zagreb, Croatia. The outcome of the competition was definitely unexpected.

  14. 制造业区域集聚与技术创新:基于负二项模型的实证分析%Industrial Agglomeration and Innovation: An Application of the Negative Binomial Model

    Institute of Scientific and Technical Information of China (English)

    张萃

    2012-01-01

    Based on the localization character of knowledge spillover, this paper examines the impact of Chinese industrial agglomeration on innovation from the spatial view by using the negative binomial regression model. The empirical evidence through the maximum likelihood estimation shows that industrial agglomeration's innovation effect is significant, which has also been supported by the extended regressions on the high-innovation industry and the high-agglomeration industry. In addition, FDI has no impact on the innovation of the high-innovation industry and the domestic firms seem to promote the innovation of the foreign firms.%本文以知识溢出的地方化(localization)特性为前提条件,从空间视点切入,首次运用负二项回归模型实证考察了中国制造业区域集聚对技术创新的影响。通过最大似然估计得出的结果表明,制造业区域集聚之技术创新效应非常显著。这一结论也得到了对高创新行业和高集聚行业拓展回归分析的支持。研究还显示,FDI对高创新行业的技术创新作用并不显著,反而出现了内资企业向外资企业逆向技术扩散的可能。

  15. MAC Layer Hurdles in BSNs

    CERN Document Server

    Ullah, Sana; Choi, Young-Woo; Lee, Hyung-Soo; Kwak, Kyung Sup

    2009-01-01

    The last few decades have seen considerable research progress in microelectronics and integrated circuits, system-on-chip design, wireless communication, and sensor technology. This progress has enabled the seamless integration of autonomous wireless sensor nodes around a human body to create a Body Sensor Network (BSN). The development of a proactive and ambulatory BSN induces a number of enormous issues and challenges. This paper presents the technical hurdles during the design and implementation of a low-power Medium Access Control (MAC) protocol for in-body and on-body sensor networks. We analyze the performance of IEEE 802.15.4 protocol for the on-body sensor network. We also provide a comprehensive insight into the heterogeneous characteristics of the in-body sensor network. A low-power technique called Pattern-Based Wake-up Table is proposed to handle the normal traffic in a BSN. The proposed technique provides a reliable solution towards low-power communication in the in-body sensor network.

  16. Hurdles in Basic Science Translation

    Directory of Open Access Journals (Sweden)

    Christina J. Perry

    2017-07-01

    Full Text Available In the past century there have been incredible advances in the field of medical research, but what hinders translation of this knowledge into effective treatment for human disease? There is an increasing focus on the failure of many research breakthroughs to be translated through the clinical trial process and into medical practice. In this mini review, we will consider some of the reasons that findings in basic medical research fail to become translated through clinical trials and into basic medical practices. We focus in particular on the way that human disease is modeled, the understanding we have of how our targets behave in vivo, and also some of the issues surrounding reproducibility of basic research findings. We will also look at some of the ways that have been proposed for overcoming these issues. It appears that there needs to be a cultural shift in the way we fund, publish and recognize quality control in scientific research. Although this is a daunting proposition, we hope that with increasing awareness and focus on research translation and the hurdles that impede it, the field of medical research will continue to inform and improve medical practice across the world.

  17. A Simulation Study of Negative Binomial Exact Test for Small Sample Micronuclei Data%基于负二项分布的确切推断在微核试验数据分析中的模拟研究

    Institute of Scientific and Technical Information of China (English)

    索瑞鑫; 仇玉兰; 王彤

    2012-01-01

    目的 通过模拟研究对几种可用于小样本微核数据统计分析的方法进行讨论,为小样本微核数据的分析提供科学依据.方法 用R软件进行编程模拟来估计不同参数下不同分析方法的Ⅰ类错误和检验功效.结果 Poisson精确概率法、Fisher精确概率法、负二项精确概率法、t检验及其变换、确切概率秩和检验的检验功效和Ⅰ型错误各不相同,其检验功效随δ和动物数n的增大而增大.其中Poisson精确概率法、Fisher精确概率法、负二项精确概率法的检验功效较高,但总体来自于负二项分布时,Poisson精确概率法、Fisher精确概率法的Ⅰ型错误较大,而负二项精确概率法Ⅰ型错误较小.结论 在小样本微核数据分析中负二项精确概率法具有检验功效较高且犯Ⅰ型错误概率小的优越性.%Objective To explore the statistical analysis method of small-sample micronuclei data by simulation studies. Methods We simulated small-sample micronuclei data,then compared the size and power of the test methods in literature for the micronuclei assay analysis. Results Compared the type I error and statistical power of several different small-sample anaysis approading for micronuclei data, etatistical analysis methods , such as Poisson exact test, Fisher exact test, Negative Binomial Exact Test,t test,t test after transformation,rank sum exact test,were considered. The power of tests increase with 8 and n. Statistical power of Poisson exact test was the highest. Fisher exact test and Negative Binomial Exact Test were lower than Poisson exact test,and higher than other statistical analysis methods. But under negative binomial distribution, type Ⅰ error was large in Poisson exact test and Fisher exact test, while it was small in Negative Binomial Exact Test. Conclusion The power of the Negative Binomial Exact was higher in spite of the lower type I error.

  18. High Adherence to Iron/Folic Acid Supplementation during Pregnancy Time among Antenatal and Postnatal Care Attendant Mothers in Governmental Health Centers in Akaki Kality Sub City, Addis Ababa, Ethiopia: Hierarchical Negative Binomial Poisson Regression

    Science.gov (United States)

    Gebreamlak, Bisratemariam; Dadi, Abel Fekadu; Atnafu, Azeb

    2017-01-01

    Background Iron deficiency during pregnancy is a risk factor for anemia, preterm delivery, and low birth weight. Iron/Folic Acid supplementation with optimal adherence can effectively prevent anemia in pregnancy. However, studies that address this area of adherence are very limited. Therefore, the current study was conducted to assess the adherence and to identify factors associated with a number of Iron/Folic Acid uptake during pregnancy time among mothers attending antenatal and postnatal care follow up in Akaki kality sub city. Methods Institutional based cross-sectional study was conducted on a sample of 557 pregnant women attending antenatal and postnatal care service. Systematic random sampling was used to select study subjects. The mothers were interviewed and the collected data was cleaned and entered into Epi Info 3.5.1 and analyzed by R version 3.2.0. Hierarchical Negative Binomial Poisson Regression Model was fitted to identify the factors associated with a number of Iron/Folic Acid uptake. Adjusted Incidence rate ratio (IRR) with 95% confidence interval (CI) was computed to assess the strength and significance of the association. Result More than 90% of the mothers were supplemented with at least one Iron/Folic Acid supplement from pill per week during their pregnancy time. Sixty percent of the mothers adhered (took four or more tablets per week) (95%CI, 56%—64.1%). Higher IRR of Iron/Folic Acid supplementation was observed among women: who received health education; which were privately employed; who achieved secondary education; and who believed that Iron/Folic Acid supplements increase blood, whereas mothers who reported a side effect, who were from families with relatively better monthly income, and who took the supplement when sick were more likely to adhere. Conclusion Adherence to Iron/Folic Acid supplement during their pregnancy time among mothers attending antenatal and postnatal care was found to be high. Activities that would address the

  19. Some Alternating Double Binomial Sums

    Institute of Scientific and Technical Information of China (English)

    ZHENG De-yin; TANG Pei-pei

    2013-01-01

    We consider some new alternating double binomial sums. By using the Lagrange inversion formula, we obtain explicit expressions of the desired results which are related to a third-order linear recursive sequence. Furthermore, their recursive relation and generating functions are obtained.

  20. Certain Binomial Sums with recursive coefficients

    CERN Document Server

    Kilic, Emrah

    2010-01-01

    In this short note, we establish some identities containing sums of binomials with coefficients satisfying third order linear recursive relations. As a result and in particular, we obtain general forms of earlier identities involving binomial coefficients and Fibonacci type sequences.

  1. Improved binomial charts for monitoring high-quality processes

    NARCIS (Netherlands)

    Albers, Willem/Wim

    2009-01-01

    For processes concerning attribute data with (very) small failure rate p, often negative binomial control charts are used. The decision whether to stop or continue is made each time r failures have occurred, for some r≥1. Finding the optimal r for detecting a given increase of p first requires align

  2. Improved binomial charts for high-quality processes

    NARCIS (Netherlands)

    Albers, Willem/Wim

    2011-01-01

    For processes concerning attribute data with (very) small failure rate p, often negative binomial control charts are used. The decision whether to stop or continue is made each time r failures have occurred, for some r≥1. Finding the optimal r for detecting a given increase of p first requires align

  3. Smoothness in Binomial Edge Ideals

    Directory of Open Access Journals (Sweden)

    Hamid Damadi

    2016-06-01

    Full Text Available In this paper we study some geometric properties of the algebraic set associated to the binomial edge ideal of a graph. We study the singularity and smoothness of the algebraic set associated to the binomial edge ideal of a graph. Some of these algebraic sets are irreducible and some of them are reducible. If every irreducible component of the algebraic set is smooth we call the graph an edge smooth graph, otherwise it is called an edge singular graph. We show that complete graphs are edge smooth and introduce two conditions such that the graph G is edge singular if and only if it satisfies these conditions. Then, it is shown that cycles and most of trees are edge singular. In addition, it is proved that complete bipartite graphs are edge smooth.

  4. 微核试验数据的Poisson和负二项回归模型拟合效果比较%Comparison of Fitting Results of Poisson Regression and Negative Binomial Regression Models for Data of Cytokinesis-block Micronucleus Test

    Institute of Scientific and Technical Information of China (English)

    郑辉烈; 王增珍; 俞慧强

    2011-01-01

    Objective To compare the fitting results of the Poisson regression model and negative binomial regression model for data of cytokinesis-block micronucleus test, and to provide a basis for statistical analysis of data of cytokinesis-block micronucleus test. Methods By using the log likelihood function,the deviance,Pearson x2 and cluster index, the fitting results of Poisson regression model and the negative binomial regression model for data of cytokinesis-block micronucleus test were evaluated. Result The ratio of log lielihood function to degree of freedom for negative binomial regression was greater than that for Poisson regression. The ratio of deviance to degree of freedom and the ratio of Pearson x2 to degree of freedom for negative binomial regression were less than those for Poisson regression. There was a significant difference in cluster index that was not equal to zero for negative binomial regression model(x2= 1 160.42, P<0.001).Conclusion The negative binomial regression model was superior to Poisson regression model for data of cytokinesis-block micronucleus test.%目的 比较Poisson和负二项回归模型对微核试验数据(每1 000个双核淋巴细胞中具有微核的淋巴细胞数)的拟合效果,为微核试验数据的模型拟合提供依据.方法 运用微核试验数据,拟合Poisson分布和负二项分布回归模型,采用对数似然函数、偏差统计量、Pearson χ2统计量和聚集性指数等指标比较2种回归模型对实例数据的拟合效果.结果 负二项回归模型对数似然函数值与自由度的比值(-2.51)大于Poisson回归模型(-3.52);负二项回归模型拟合优度统计量-偏差统计量和Pearson χ2统计量与对应的自由度比值(1.16和1.07)小于Poisson回归模型;聚集性指数的似然比检验(H0:k=0)显示,聚集性指数不等于0具有统计学意义(χ2=1 160.42,P<0.001).结论对于微核试验数据,拟合负二项回归模型要优于Poisson回归模型.

  5. Defining the critical hurdles in cancer immunotherapy

    DEFF Research Database (Denmark)

    Fox, Bernard A; Schendel, Dolores J; Butterfield, Lisa H

    2011-01-01

    Scientific discoveries that provide strong evidence of antitumor effects in preclinical models often encounter significant delays before being tested in patients with cancer. While some of these delays have a scientific basis, others do not. We need to do better. Innovative strategies need to move...... of cancer immunotherapy. With consensus on these hurdles, international working groups could be developed to make recommendations vetted by the participating organizations. These recommendations could then be considered by regulatory bodies, governmental and private funding agencies, pharmaceutical...... in this report. Some of the identified hurdles impede all investigators; others hinder investigators only in certain regions or institutions or are more relevant to specific types of immunotherapy or first-in-humans studies. Each of these hurdles can significantly delay clinical translation of promising advances...

  6. Defining the critical hurdles in cancer immunotherapy

    Directory of Open Access Journals (Sweden)

    Fox Bernard A

    2011-12-01

    Full Text Available Abstract Scientific discoveries that provide strong evidence of antitumor effects in preclinical models often encounter significant delays before being tested in patients with cancer. While some of these delays have a scientific basis, others do not. We need to do better. Innovative strategies need to move into early stage clinical trials as quickly as it is safe, and if successful, these therapies should efficiently obtain regulatory approval and widespread clinical application. In late 2009 and 2010 the Society for Immunotherapy of Cancer (SITC, convened an "Immunotherapy Summit" with representatives from immunotherapy organizations representing Europe, Japan, China and North America to discuss collaborations to improve development and delivery of cancer immunotherapy. One of the concepts raised by SITC and defined as critical by all parties was the need to identify hurdles that impede effective translation of cancer immunotherapy. With consensus on these hurdles, international working groups could be developed to make recommendations vetted by the participating organizations. These recommendations could then be considered by regulatory bodies, governmental and private funding agencies, pharmaceutical companies and academic institutions to facilitate changes necessary to accelerate clinical translation of novel immune-based cancer therapies. The critical hurdles identified by representatives of the collaborating organizations, now organized as the World Immunotherapy Council, are presented and discussed in this report. Some of the identified hurdles impede all investigators; others hinder investigators only in certain regions or institutions or are more relevant to specific types of immunotherapy or first-in-humans studies. Each of these hurdles can significantly delay clinical translation of promising advances in immunotherapy yet if overcome, have the potential to improve outcomes of patients with cancer.

  7. Problems on Divisibility of Binomial Coefficients

    Science.gov (United States)

    Osler, Thomas J.; Smoak, James

    2004-01-01

    Twelve unusual problems involving divisibility of the binomial coefficients are represented in this article. The problems are listed in "The Problems" section. All twelve problems have short solutions which are listed in "The Solutions" section. These problems could be assigned to students in any course in which the binomial theorem and Pascal's…

  8. PENERAPAN REGRESI BINOMIAL NEGATIF UNTUK MENGATASI OVERDISPERSI PADA REGRESI POISSON

    Directory of Open Access Journals (Sweden)

    PUTU SUSAN PRADAWATI

    2013-09-01

    Full Text Available Poisson regression was used to analyze the count data which Poisson distributed. Poisson regression analysis requires state equidispersion, in which the mean value of the response variable is equal to the value of the variance. However, there are deviations in which the value of the response variable variance is greater than the mean. This is called overdispersion. If overdispersion happens and Poisson Regression analysis is being used, then underestimated standard errors will be obtained. Negative Binomial Regression can handle overdispersion because it contains a dispersion parameter. From the simulation data which experienced overdispersion in the Poisson Regression model it was found that the Negative Binomial Regression was better than the Poisson Regression model.

  9. PENERAPAN REGRESI BINOMIAL NEGATIF UNTUK MENGATASI OVERDISPERSI PADA REGRESI POISSON

    Directory of Open Access Journals (Sweden)

    PUTU SUSAN PRADAWATI

    2013-09-01

    Full Text Available Poisson regression was used to analyze the count data which Poisson distributed. Poisson regression analysis requires state equidispersion, in which the mean value of the response variable is equal to the value of the variance. However, there are deviations in which the value of the response variable variance is greater than the mean. This is called overdispersion. If overdispersion happens and Poisson Regression analysis is being used, then underestimated standard errors will be obtained. Negative Binomial Regression can handle overdispersion because it contains a dispersion parameter. From the simulation data which experienced overdispersion in the Poisson Regression model it was found that the Negative Binomial Regression was better than the Poisson Regression model.

  10. Predicting Cumulative Incidence Probability by Direct Binomial Regression

    DEFF Research Database (Denmark)

    Scheike, Thomas H.; Zhang, Mei-Jie

    Binomial modelling; cumulative incidence probability; cause-specific hazards; subdistribution hazard......Binomial modelling; cumulative incidence probability; cause-specific hazards; subdistribution hazard...

  11. Calculating Cumulative Binomial-Distribution Probabilities

    Science.gov (United States)

    Scheuer, Ernest M.; Bowerman, Paul N.

    1989-01-01

    Cumulative-binomial computer program, CUMBIN, one of set of three programs, calculates cumulative binomial probability distributions for arbitrary inputs. CUMBIN, NEWTONP (NPO-17556), and CROSSER (NPO-17557), used independently of one another. Reliabilities and availabilities of k-out-of-n systems analyzed. Used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. Used for calculations of reliability and availability. Program written in C.

  12. Distribution-free Inference of Zero-inated Binomial Data for Longitudinal Studies.

    Science.gov (United States)

    He, H; Wang, W J; Hu, J; Gallop, R; Crits-Christoph, P; Xia, Y L

    2015-10-01

    Count reponses with structural zeros are very common in medical and psychosocial research, especially in alcohol and HIV research, and the zero-inflated poisson (ZIP) and zero-inflated negative binomial (ZINB) models are widely used for modeling such outcomes. However, as alcohol drinking outcomes such as days of drinkings are counts within a given period, their distributions are bounded above by an upper limit (total days in the period) and thus inherently follow a binomial or zero-inflated binomial (ZIB) distribution, rather than a Poisson or zero-inflated Poisson (ZIP) distribution, in the presence of structural zeros. In this paper, we develop a new semiparametric approach for modeling zero-inflated binomial (ZIB)-like count responses for cross-sectional as well as longitudinal data. We illustrate this approach with both simulated and real study data.

  13. Artificial insemination history: hurdles and milestones.

    Science.gov (United States)

    Ombelet, W; Van Robays, J

    2015-01-01

    Artificial insemination with homologous (AIH) or donor semen (AID) is nowadays a very popular treatment procedure used for many subfertile women worldwide. The rationale behind artificial insemination is to increase gamete density at the site of fertilisation. The sequence of events leading to today's common use of artificial insemination traces back to scientific studies and experimentation many centuries ago. Modern techniques used in human artificial insemination programmes are mostly adapted from the work on cattle by dairy farmers wishing to improve milk production by using artificial insemination with sperm of selected bulls with well chosen genetic traits. The main reason for the renewed interest in artificial insemination in human was associated with the refinement of techniques for the preparation of washed motile spermatozoa in the early years of IVF. The history of artificial insemination is reviewed with particular interest to the most important hurdles and milestones.

  14. Changes in technique within a sprint hurdle run.

    Science.gov (United States)

    Salo, Aki I T; Scarborough, Simon

    2006-07-01

    The aim of this study was to understand changes in technique within an athlete's own performance during a sprint hurdles run. Four athletes performed a training session containing four trials each over 10 hurdles. Clearances at hurdles three and nine were videotaped from a side view and manually digitised. All athletes in this study yielded a lower running speed over the hurdle at the ninth hurdle in comparison to the third hurdle in each run. All athletes also showed further signs of potential tiredness in the clearances of the ninth hurdle. Interestingly, these changes in technique varied among the athletes. This poses challenges to coaches, as they need to evaluate individually what changes in training should be introduced to keep the quality of clearances as high as possible throughout training. To match more closely the velocities to those in competitions, consideration could be given in training to shorten gradually the distances between the hurdles more during the latter part of the run, although this should be individually checked, based on the athlete. This way, athletes could learn to clear the hurdle with a higher horizontal velocity, even when fatigue is potentially influencing the performance.

  15. Biased binomial assessment of cross-validated estimation of classification accuracies illustrated in diagnosis predictions

    Directory of Open Access Journals (Sweden)

    Quentin Noirhomme

    2014-01-01

    Full Text Available Multivariate classification is used in neuroimaging studies to infer brain activation or in medical applications to infer diagnosis. Their results are often assessed through either a binomial or a permutation test. Here, we simulated classification results of generated random data to assess the influence of the cross-validation scheme on the significance of results. Distributions built from classification of random data with cross-validation did not follow the binomial distribution. The binomial test is therefore not adapted. On the contrary, the permutation test was unaffected by the cross-validation scheme. The influence of the cross-validation was further illustrated on real-data from a brain–computer interface experiment in patients with disorders of consciousness and from an fMRI study on patients with Parkinson disease. Three out of 16 patients with disorders of consciousness had significant accuracy on binomial testing, but only one showed significant accuracy using permutation testing. In the fMRI experiment, the mental imagery of gait could discriminate significantly between idiopathic Parkinson's disease patients and healthy subjects according to the permutation test but not according to the binomial test. Hence, binomial testing could lead to biased estimation of significance and false positive or negative results. In our view, permutation testing is thus recommended for clinical application of classification with cross-validation.

  16. Biased binomial assessment of cross-validated estimation of classification accuracies illustrated in diagnosis predictions.

    Science.gov (United States)

    Noirhomme, Quentin; Lesenfants, Damien; Gomez, Francisco; Soddu, Andrea; Schrouff, Jessica; Garraux, Gaëtan; Luxen, André; Phillips, Christophe; Laureys, Steven

    2014-01-01

    Multivariate classification is used in neuroimaging studies to infer brain activation or in medical applications to infer diagnosis. Their results are often assessed through either a binomial or a permutation test. Here, we simulated classification results of generated random data to assess the influence of the cross-validation scheme on the significance of results. Distributions built from classification of random data with cross-validation did not follow the binomial distribution. The binomial test is therefore not adapted. On the contrary, the permutation test was unaffected by the cross-validation scheme. The influence of the cross-validation was further illustrated on real-data from a brain-computer interface experiment in patients with disorders of consciousness and from an fMRI study on patients with Parkinson disease. Three out of 16 patients with disorders of consciousness had significant accuracy on binomial testing, but only one showed significant accuracy using permutation testing. In the fMRI experiment, the mental imagery of gait could discriminate significantly between idiopathic Parkinson's disease patients and healthy subjects according to the permutation test but not according to the binomial test. Hence, binomial testing could lead to biased estimation of significance and false positive or negative results. In our view, permutation testing is thus recommended for clinical application of classification with cross-validation.

  17. An Interesting Application of the Binomial Distribution.

    Science.gov (United States)

    Newell, G. J.; MacFarlane, J. D.

    1984-01-01

    Presents an application of the binomial distribution in which the distribution is used to detect differences between the sensory properties of food products. Included is a BASIC computer program listing used to generate triangle and duo-trio test results. (JN)

  18. Adaptive bayesian analysis for binomial proportions

    CSIR Research Space (South Africa)

    Das, Sonali

    2008-10-01

    Full Text Available The authors consider the problem of statistical inference of binomial proportions for non-matched, correlated samples, under the Bayesian framework. Such inference can arise when the same group is observed at a different number of times with the aim...

  19. Examining Teachers' Hurdles to `Science for All'

    Science.gov (United States)

    Southerland, Sherry; Gallard, Alejandro; Callihan, Laurie

    2011-11-01

    The goal of this research is to identify science teachers' beliefs and conceptions that play an important role in shaping their understandings of and attempts to enact inclusive science teaching practices. We examined the work products, both informal (online discussions, email exchanges) and formal (papers, unit plans, peer reviews), of 14 teachers enrolled in a master's degree course focused on diversity in science teaching and learning. These emerging understandings were member-checked via a series of interviews with a subset of these teachers. Our analysis was conducted in two stages: (1) describing the difficulties the teachers identified for themselves in their attempts to teach science to a wide range of students in their classes and (2) analyzing these self-identified barriers for underlying beliefs and conceptions that serve to prohibit or allow for the teachers' understanding and enactment of equitable science instruction. The teachers' self-identified barriers were grouped into three categories: students, broader social infrastructure, and self. The more fundamental barriers identified included teacher beliefs about the ethnocentrism of the mainstream, essentialism/individualism, and beliefs about the meritocracy of schooling. The implications of these hurdles for science teacher education are discussed.

  20. Hurdles in bacteriophage therapy: deconstructing the parameters.

    Science.gov (United States)

    Tsonos, Jessica; Vandenheuvel, Dieter; Briers, Yves; De Greve, Henri; Hernalsteens, Jean-Pierre; Lavigne, Rob

    2014-07-16

    Bacterial infections in animals impact our food production, leading to economic losses due to food rejection and the need for preventive and curative measures. Since the onset of the antibiotic era, the rise of antibiotic-resistant pathogens is causing scares in health care and food producing facilities worldwide. In the search of new therapeutics, re-evaluation of bacteriophage (phage) therapy, using naturally occurring bacterial viruses to tackle infections, is gaining interest. Many studies report about phage therapy success, showing the value and power of these natural viruses. Although phages carry some interesting traits and their basic biology is now well understood, this review argues that phage therapy has not revealed all of its secrets and many parameters remain understudied, making the outcome of phage therapy highly variable depending on the disease incidence. These difficulties include poorly understood mechanisms of phage penetration and distribution throughout the body, the variable expression and accessibility of phage receptors on the bacterial host in in vivo conditions and the unusual (non-linear) phage pharmacokinetics. These parameters are not easily measured in realistic in vivo settings, but are nevertheless important hurdles to overcome the high variability of phage therapy trials. This critical approach is in accordance with Goethe's statement; "Difficulties increase the nearer we get to the goal". However, since the importance of the goal itself also rises, both difficulties and goal justify the need for additional in depth research in this domain. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Tomography of binomial states of the radiation field

    NARCIS (Netherlands)

    Bazrafkan, MR; Man'ko, [No Value

    2004-01-01

    The symplectic, optical, and photon-number tomographic symbols of binomial states of the radiation field are studied. Explicit relations for all tomograms of the binomial states are obtained. Two measures for nonclassical properties of these states are discussed.

  2. Tomography of binomial states of the radiation field

    NARCIS (Netherlands)

    Bazrafkan, MR; Man'ko, [No Value

    2004-01-01

    The symplectic, optical, and photon-number tomographic symbols of binomial states of the radiation field are studied. Explicit relations for all tomograms of the binomial states are obtained. Two measures for nonclassical properties of these states are discussed.

  3. Effect of Hurdle Technology in Food Preservation: A Review.

    Science.gov (United States)

    Singh, Shiv; Shalini, Rachana

    2016-01-01

    Hurdle technology is used in industrialized as well as in developing countries for the gentle but effective preservation of foods. Hurdle technology was developed several years ago as a new concept for the production of safe, stable, nutritious, tasty, and economical foods. Previously hurdle technology, i.e., a combination of preservation methods, was used empirically without much knowledge of the governing principles. The intelligent application of hurdle technology has become more prevalent now, because the principles of major preservative factors for foods (e.g., temperature, pH, aw, Eh, competitive flora), and their interactions, became better known. Recently, the influence of food preservation methods on the physiology and behavior of microorganisms in foods, i.e. their homeostasis, metabolic exhaustion, stress reactions, are taken into account, and the novel concept of multi-target food preservation emerged. The present contribution reviews the concept of the potential hurdles for foods, the hurdle effect, and the hurdle technology for the prospects of the future goal of a multi-target preservation of foods.

  4. Generalized binomial distribution in photon statistics

    Science.gov (United States)

    Ilyin, Aleksey

    2015-01-01

    The photon-number distribution between two parts of a given volume is found for an arbitrary photon statistics. This problem is related to the interaction of a light beam with a macroscopic device, for example a diaphragm, that separates the photon flux into two parts with known probabilities. To solve this problem, a Generalized Binomial Distribution (GBD) is derived that is applicable to an arbitrary photon statistics satisfying probability convolution equations. It is shown that if photons obey Poisson statistics then the GBD is reduced to the ordinary binomial distribution, whereas in the case of Bose- Einstein statistics the GBD is reduced to the Polya distribution. In this case, the photon spatial distribution depends on the phase-space volume occupied by the photons. This result involves a photon bunching effect, or collective behavior of photons that sharply differs from the behavior of classical particles. It is shown that the photon bunching effect looks similar to the quantum interference effect.

  5. A Negative Binomial Regression Model for Accuracy Tests

    Science.gov (United States)

    Hung, Lai-Fa

    2012-01-01

    Rasch used a Poisson model to analyze errors and speed in reading tests. An important property of the Poisson distribution is that the mean and variance are equal. However, in social science research, it is very common for the variance to be greater than the mean (i.e., the data are overdispersed). This study embeds the Rasch model within an…

  6. Shareholder Value or Competitive Advantage? Evidence from Hurdle Rates

    OpenAIRE

    Ciaran Driver; Paul Temple

    2004-01-01

    Economic theory suggests several plausible reasons why firms may employ hurdle rates for capital investment appraisal that differ from discount rates. Using a sample of business units from the PIMS data bank of North American companies we find that hurdle rates are frequently below and also frequently above matched data on discount rates. Using multinomial logit analysis we find that variables representing the opportunity for strategic investment or the motivation for such investment increase...

  7. Binomial ARMA count series from renewal processes

    CERN Document Server

    Koshkin, Sergiy

    2011-01-01

    This paper describes a new method for generating stationary integer-valued time series from renewal processes. We prove that if the lifetime distribution of renewal processes is nonlattice and the probability generating function is rational, then the generated time series satisfy causal and invertible ARMA type stochastic difference equations. The result provides an easy method for generating integer-valued time series with ARMA type autocovariance functions. Examples of generating binomial ARMA(p,p-1) series from lifetime distributions with constant hazard rates after lag p are given as an illustration. An estimation method is developed for the AR(p) cases.

  8. A Binomial Integer-Valued ARCH Model.

    Science.gov (United States)

    Ristić, Miroslav M; Weiß, Christian H; Janjić, Ana D

    2016-11-01

    We present an integer-valued ARCH model which can be used for modeling time series of counts with under-, equi-, or overdispersion. The introduced model has a conditional binomial distribution, and it is shown to be strictly stationary and ergodic. The unknown parameters are estimated by three methods: conditional maximum likelihood, conditional least squares and maximum likelihood type penalty function estimation. The asymptotic distributions of the estimators are derived. A real application of the novel model to epidemic surveillance is briefly discussed. Finally, a generalization of the introduced model is considered by introducing an integer-valued GARCH model.

  9. Generalized binomial distribution in photon statistics

    Directory of Open Access Journals (Sweden)

    Ilyin Aleksey

    2015-01-01

    Full Text Available The photon-number distribution between two parts of a given volume is found for an arbitrary photon statistics. This problem is related to the interaction of a light beam with a macroscopic device, for example a diaphragm, that separates the photon flux into two parts with known probabilities. To solve this problem, a Generalized Binomial Distribution (GBD is derived that is applicable to an arbitrary photon statistics satisfying probability convolution equations. It is shown that if photons obey Poisson statistics then the GBD is reduced to the ordinary binomial distribution, whereas in the case of Bose- Einstein statistics the GBD is reduced to the Polya distribution. In this case, the photon spatial distribution depends on the phase-space volume occupied by the photons. This result involves a photon bunching effect, or collective behavior of photons that sharply differs from the behavior of classical particles. It is shown that the photon bunching effect looks similar to the quantum interference effect.

  10. Application of zero-inflated negative binomial model to study the pattern of Ascaris lumbricoides and hookworm re-infection%零膨胀的负二项模型在蛔虫与钩虫再感染模式研究中的应用

    Institute of Scientific and Technical Information of China (English)

    王骏; 梁松; 陈颖丹; 李华忠; 汤林华

    2014-01-01

    Objective Use zero-inflated negative binomial model for modeling the pattern of Ascoris lumbricoides and hookworm re-infection.Methods Field survey was carried out in three villages:Qiuchang in Yibin City of Sichuan Province,Tangnan in Jinxian County of Jiangxi Province,and Sanhe in Yueyang County of Hunan Province.The survey consisted of baseline stool examination and treatment,re-examination after one month and one year,and questionnaire survey.Zero-inflated negative binomial model was applied to fit the egg count data collected after one year,meanwhile,the risk factors for the re-infection occurrence and intensity were evaluated.Results Totally 374 subjects were recruited in the survey after one year.The prevalences of Ascaris lumbricoides and hookworm at baseline 38.08%(139/365) and 39.17%(141/360).The re-infection rates of Ascaris lumbricoides and hookworm one year after treatment were 15.89% (58/365) and 8.89% (32/360),respectively.A.lumbricoides model showed:the higher infection intensity before treatment,the higher risk of re-infection occurrence(OR=1.94,95%CI:1.33~2.81),high level of household electrical appliances and not drinking un-boiled water were protective factors.The risk of re-infection in age group 15~44 years and 45~64 years was lower than that in group 5~14 years significantly.The higher infection intensity before treatment,the higher risk of high re-infection intensity after treatment (OR=1.56,95%CI:1.10~2.23).Compared to age group 5~14 years,15~44 years and 65~70 years had low risk of getting high re-infection intensity.Not drinking unboiled water was also a protective factor for acquiring high intensity.Hookworm model showed:the higher infection intensity before treatment,the higher risk of re-infection occurrence (OR =3.97,95%CI:2.07~7.60),living in brick house opposed to adobe house was protective factor for re-infection.Compared to age group 5~14 years,the other 3 age groups had higher risk of getting

  11. Time accelerated Monte Carlo simulations of biological networks using the binomial tau-leap method.

    Science.gov (United States)

    Chatterjee, Abhijit; Mayawala, Kapil; Edwards, Jeremy S; Vlachos, Dionisios G

    2005-05-01

    Developing a quantitative understanding of intracellular networks requires simulations and computational analyses. However, traditional differential equation modeling tools are often inadequate due to the stochasticity of intracellular reaction networks that can potentially influence the phenotypic characteristics. Unfortunately, stochastic simulations are computationally too intense for most biological systems. Herein, we have utilized the recently developed binomial tau-leap method to carry out stochastic simulations of the epidermal growth factor receptor induced mitogen activated protein kinase cascade. Results indicate that the binomial tau-leap method is computationally 100-1000 times more efficient than the exact stochastic simulation algorithm of Gillespie. Furthermore, the binomial tau-leap method avoids negative populations and accurately captures the species populations along with their fluctuations despite the large difference in their size. http://www.dion.che.udel.edu/multiscale/Introduction.html. Fortran 90 code available for academic use by email. Details about the binomial tau-leap algorithm, software and a manual are available at the above website.

  12. Extending the Binomial Checkpointing Technique for Resilience

    Energy Technology Data Exchange (ETDEWEB)

    Walther, Andrea; Narayanan, Sri Hari Krishna

    2016-10-10

    In terms of computing time, adjoint methods offer a very attractive alternative to compute gradient information, re- quired, e.g., for optimization purposes. However, together with this very favorable temporal complexity result comes a memory requirement that is in essence proportional with the operation count of the underlying function, e.g., if algo- rithmic differentiation is used to provide the adjoints. For this reason, checkpointing approaches in many variants have become popular. This paper analyzes an extension of the so-called binomial approach to cover also possible failures of the computing systems. Such a measure of precaution is of special interest for massive parallel simulations and adjoint calculations where the mean time between failure of the large scale computing system is smaller than the time needed to complete the calculation of the adjoint information. We de- scribe the extensions of standard checkpointing approaches required for such resilience, provide a corresponding imple- mentation and discuss numerical results.

  13. Penggunaan Model Binomial Pada Penentuan Harga Opsi Saham Karyawan

    Directory of Open Access Journals (Sweden)

    Dara Puspita Anggraeni

    2015-11-01

    Full Text Available Binomial Model for Valuing Employee Stock Options. Employee Stock Options (ESO differ from standard exchange-traded options. The three main differences in a valuation model for employee stock options : Vesting Period, Exit Rate and Non-Transferability. In this thesis, the model for valuing employee stock options discussed. This model are implement with a generalized binomial model.

  14. Convergence Properties of Kemp's q-Binomial Distribution

    OpenAIRE

    Gerhold, Stefan; Zeiner, Martin

    2008-01-01

    We consider Kemp's q-analogue of the binomial distribution. Several convergence results involving the classical binomial, the Heine, the discrete normal, and the Poisson distribution are established. Some of them are q-analogues of classical convergence properties. Besides elementary estimates, we apply Mellin transform asymptotics.

  15. Bayesian Analysis for Binomial Models with Generalized Beta Prior Distributions.

    Science.gov (United States)

    Chen, James J.; Novick, Melvin, R.

    1984-01-01

    The Libby-Novick class of three-parameter generalized beta distributions is shown to provide a rich class of prior distributions for the binomial model that removes some restrictions of the standard beta class. A numerical example indicates the desirability of using these wider classes of densities for binomial models. (Author/BW)

  16. Preservation of South African steamed bread using hurdle technology

    CSIR Research Space (South Africa)

    Lombard, GE

    2000-01-01

    Full Text Available To transform traditional South African steamed bread, a dumpling-like product, into a convenient ready-to-eat form in a can, the application of various hurdles was investigated. Prevention of the growth of Clostridium botulinum in this low acid...

  17. NUMERICAL ANALYSIS ON BINOMIAL TREE METHODS FOR AMERICAN LOOKBACK OPTIONS

    Institute of Scientific and Technical Information of China (English)

    戴民

    2001-01-01

    Lookback options are path-dependent options. In general, the binomial tree methods,as the most popular approaches to pricing options, involve a path dependent variable as well as the underlying asset price for lookback options. However, for floating strike lookback options, a single-state variable binomial tree method can be constructed. This paper is devoted to the convergence analysis of the single-state binomial tree methods both for discretely and continuously monitored American floating strike lookback options. We also investigate some properties of such options, including effects of expiration date, interest rate and dividend yield on options prices,properties of optimal exercise boundaries and so on.

  18. Quiver mutation sequences and $q$-binomial identities

    CERN Document Server

    Kato, Akishi; Terashima, Yuji

    2016-01-01

    In this paper, first we introduce a quantity called a partition function for a quiver mutation sequence. The partition function is a generating function whose weight is a $q$-binomial associated with each mutation. Then, we show that the partition function can be expressed as a ratio of products of quantum dilogarithms. This provides a systematic way of constructing various $q$-binomial multisum identities.

  19. Detecting non-binomial sex allocation when developmental mortality operates.

    Science.gov (United States)

    Wilkinson, Richard D; Kapranas, Apostolos; Hardy, Ian C W

    2016-11-01

    Optimal sex allocation theory is one of the most intricately developed areas of evolutionary ecology. Under a range of conditions, particularly under population sub-division, selection favours sex being allocated to offspring non-randomly, generating non-binomial variances of offspring group sex ratios. Detecting non-binomial sex allocation is complicated by stochastic developmental mortality, as offspring sex can often only be identified on maturity with the sex of non-maturing offspring remaining unknown. We show that current approaches for detecting non-binomiality have limited ability to detect non-binomial sex allocation when developmental mortality has occurred. We present a new procedure using an explicit model of sex allocation and mortality and develop a Bayesian model selection approach (available as an R package). We use the double and multiplicative binomial distributions to model over- and under-dispersed sex allocation and show how to calculate Bayes factors for comparing these alternative models to the null hypothesis of binomial sex allocation. The ability to detect non-binomial sex allocation is greatly increased, particularly in cases where mortality is common. The use of Bayesian methods allows for the quantification of the evidence in favour of each hypothesis, and our modelling approach provides an improved descriptive capability over existing approaches. We use a simulation study to demonstrate substantial improvements in power for detecting non-binomial sex allocation in situations where current methods fail, and we illustrate the approach in real scenarios using empirically obtained datasets on the sexual composition of groups of gregarious parasitoid wasps.

  20. Recombining binomial tree for constant elasticity of variance process

    OpenAIRE

    Hi Jun Choe; Jeong Ho Chu; So Jeong Shin

    2014-01-01

    The theme in this paper is the recombining binomial tree to price American put option when the underlying stock follows constant elasticity of variance(CEV) process. Recombining nodes of binomial tree are decided from finite difference scheme to emulate CEV process and the tree has a linear complexity. Also it is derived from the differential equation the asymptotic envelope of the boundary of tree. Conducting numerical experiments, we confirm the convergence and accuracy of the pricing by ou...

  1. Hurdles in anticancer drug development from a regulatory perspective.

    Science.gov (United States)

    Jonsson, Bertil; Bergh, Jonas

    2012-02-21

    Between January 2001 and January 2012, 48 new medicinal products for cancer treatment were licensed within the EU, and 77 new indications were granted for products already licensed. In some cases, a major improvement to existing therapies was achieved, for example, trastuzumab in breast cancer. In other cases, new fields for effective drug therapy opened up, such as in chronic myeloid leukemia, and renal-cell carcinoma. In most cases, however, the benefit-risk balance was considered to be only borderline favorable. Based on our assessment of advice procedures for marketing authorization, 'need for speed' seems to be the guiding principle in anticancer drug development. Although, for drugs that make a difference, early licensure is of obvious importance to patients, this is less evident in the case of borderline drugs. Without proper incentives and with hurdles inside and outside companies, a change in drug development cannot be expected; drugs improving benefit-risk modestly over available therapies will be brought forward towards licensure. In this Perspectives article, we discuss some hurdles to biomarker-driven drug development and provide some suggestions to overcome them.

  2. QUANTUM THEORY FOR THE BINOMIAL MODEL IN FINANCE THEORY

    Institute of Scientific and Technical Information of China (English)

    CHEN Zeqian

    2004-01-01

    In this paper, a quantum model for the binomial market in finance is proposed. We show that its risk-neutral world exhibits an intriguing structure as a disk in the unit ball of R3, whose radius is a function of the risk-free interest rate with two thresholds which prevent arbitrage opportunities from this quantum market. Furthermore, from the quantum mechanical point of view we re-deduce the Cox-Ross-Rubinstein binomial option pricing formula by considering Maxwell-Boltzmann statistics of the system of N distinguishable particles.

  3. Estimation of Log-Linear-Binomial Distribution with Applications

    Directory of Open Access Journals (Sweden)

    Elsayed Ali Habib

    2010-01-01

    Full Text Available Log-linear-binomial distribution was introduced for describing the behavior of the sum of dependent Bernoulli random variables. The distribution is a generalization of binomial distribution that allows construction of a broad class of distributions. In this paper, we consider the problem of estimating the two parameters of log-linearbinomial distribution by moment and maximum likelihood methods. The distribution is used to fit genetic data and to obtain the sampling distribution of the sign test under dependence among trials.

  4. Binomial lattice for pricing Asian options on yields

    Institute of Scientific and Technical Information of China (English)

    杨德生

    2003-01-01

    An efficient binomial lattice for pricing Asian options on yields is established under the affine term structure model. In order to reconnect the path of the discrete lattice,the technique of D. Nelson and K. Ramaswamy is used to transform a stochastic interest rate process into a stochastic diffusion with unit volatility. By the binomial lattice and linear interpolation,the prices of Asian options on yields can be obtained. As the number of nodes in the tree structure grows linearly with the number of time steps, the computational speed is improved. The numerical experiments to verify the validity of the lattice are also provided.

  5. Una prueba de razón de verosimilitudes para discriminar entre la distribución Poisson, Binomial y Binomial Negativa.

    OpenAIRE

    López Martínez, Laura Elizabeth

    2010-01-01

    En este trabajo se realiza inferencia estadística en la distribución Binomial Negativa Generalizada (BNG) y los modelos que anida, los cuales son Binomial, Binomial Negativa y Poisson. Se aborda el problema de estimación de parámetros en la distribución BNG y se propone una prueba de razón de verosimilitud generalizada para discernir si un conjunto de datos se ajusta en particular al modelo Binomial, Binomial Negativa o Poisson. Además, se estudian las potencias y tamaños de la prueba p...

  6. Currency lookback options and observation frequency: A binomial approach

    NARCIS (Netherlands)

    T.H.F. Cheuk; A.C.F. Vorst (Ton)

    1997-01-01

    textabstractIn the last decade, interest in exotic options has been growing, especially in the over-the-counter currency market. In this paper we consider Iookback currency options, which are path-dependent. We show that a one-state variable binomial model for currency Iookback options can be constr

  7. I Remember You: Independence and the Binomial Model

    Science.gov (United States)

    Levine, Douglas W.; Rockhill, Beverly

    2006-01-01

    We focus on the problem of ignoring statistical independence. A binomial experiment is used to determine whether judges could match, based on looks alone, dogs to their owners. The experimental design introduces dependencies such that the probability of a given judge correctly matching a dog and an owner changes from trial to trial. We show how…

  8. On the Mean Absolute Error in Inverse Binomial Sampling

    OpenAIRE

    Mendo, Luis

    2009-01-01

    A closed-form expression and an upper bound are obtained for the mean absolute error of the unbiased estimator of a probability in inverse binomial sampling. The results given permit the estimation of an arbitrary probability with a prescribed level of the normalized mean absolute error.

  9. A Neutrosophic Binomial Factorial Theorem with their Refrains

    OpenAIRE

    Khalid, Huda; Smarandache, Florentin; Essa, Ahmed

    2016-01-01

    The Neutrosophic Precalculus and the Neutrosophic Calculus can be developed in many ways, depending on the types of indeterminacy one has and on the method used to deal with such indeterminacy. This article is innovative since the form of neutrosophic binomial factorial theorem was constructed in addition to its refrains.

  10. Using the {Beta}-binomial distribution to characterize forest health

    Energy Technology Data Exchange (ETDEWEB)

    Zarnoch, S. J. [USDA Forest Service, Southern Research Station, Athens, GA (United States); Anderson, R.L.; Sheffield, R. M. [USDA Forest Service, Southern Research Station, Asheville, NC (United States)

    1995-03-01

    Forest health monitoring programs often use base variables which are dichotomous (i e. alive/dead, damaged/undamaged) to describe the health of trees. Typical sampling designs usually consist of randomly or systematically chosen clusters of trees for observation.It was claimed that contagiousness of diseases for example may result in non-uniformity of affected trees, so that distribution of the proportions, rather than simply the mean proportion, becomes important. The use of the {Beta}-binomial model was suggested for such cases. Use of the {Beta}-binomial distribution model applied in forest health analyses, was described.. Data on dogwood anthracnose (caused by Discula destructiva), a disease of flowering dogwood (Cornus florida L.), was used to illustrate the utility of the model. The {Beta}-binomial model allowed the detection of different distributional patterns of dogwood anthracnose over time and space. Results led to further speculation regarding the cause of the patterns. Traditional proportion analyses like ANOVA would not have detected the trends found using the {Beta}-binomial model, until more distinct patterns had evolved at a later date. The model was said to be flexible and require no special weighting or transformations of data.Another advantage claimed was its ability to handle unequal sample sizes.

  11. Estimating the Parameters of the Beta-Binomial Distribution.

    Science.gov (United States)

    Wilcox, Rand R.

    1979-01-01

    For some situations the beta-binomial distribution might be used to describe the marginal distribution of test scores for a particular population of examinees. Several different methods of approximating the maximum likelihood estimate were investigated, and it was found that the Newton-Raphson method should be used when it yields admissable…

  12. Fitting Additive Binomial Regression Models with the R Package blm

    Directory of Open Access Journals (Sweden)

    Stephanie Kovalchik

    2013-09-01

    Full Text Available The R package blm provides functions for fitting a family of additive regression models to binary data. The included models are the binomial linear model, in which all covariates have additive effects, and the linear-expit (lexpit model, which allows some covariates to have additive effects and other covariates to have logisitc effects. Additive binomial regression is a model of event probability, and the coefficients of linear terms estimate covariate-adjusted risk differences. Thus, in contrast to logistic regression, additive binomial regression puts focus on absolute risk and risk differences. In this paper, we give an overview of the methodology we have developed to fit the binomial linear and lexpit models to binary outcomes from cohort and population-based case-control studies. We illustrate the blm packages methods for additive model estimation, diagnostics, and inference with risk association analyses of a bladder cancer nested case-control study in the NIH-AARP Diet and Health Study.

  13. Stochastic analysis of complex reaction networks using binomial moment equations.

    Science.gov (United States)

    Barzel, Baruch; Biham, Ofer

    2012-09-01

    The stochastic analysis of complex reaction networks is a difficult problem because the number of microscopic states in such systems increases exponentially with the number of reactive species. Direct integration of the master equation is thus infeasible and is most often replaced by Monte Carlo simulations. While Monte Carlo simulations are a highly effective tool, equation-based formulations are more amenable to analytical treatment and may provide deeper insight into the dynamics of the network. Here, we present a highly efficient equation-based method for the analysis of stochastic reaction networks. The method is based on the recently introduced binomial moment equations [Barzel and Biham, Phys. Rev. Lett. 106, 150602 (2011)]. The binomial moments are linear combinations of the ordinary moments of the probability distribution function of the population sizes of the interacting species. They capture the essential combinatorics of the reaction processes reflecting their stoichiometric structure. This leads to a simple and transparent form of the equations, and allows a highly efficient and surprisingly simple truncation scheme. Unlike ordinary moment equations, in which the inclusion of high order moments is prohibitively complicated, the binomial moment equations can be easily constructed up to any desired order. The result is a set of equations that enables the stochastic analysis of complex reaction networks under a broad range of conditions. The number of equations is dramatically reduced from the exponential proliferation of the master equation to a polynomial (and often quadratic) dependence on the number of reactive species in the binomial moment equations. The aim of this paper is twofold: to present a complete derivation of the binomial moment equations; to demonstrate the applicability of the moment equations for a representative set of example networks, in which stochastic effects play an important role.

  14. Generalized Binomial Convolution of the mth Powers of the Consecutive Integers with the General Fibonacci Sequence

    Directory of Open Access Journals (Sweden)

    Kılıç Emrah

    2016-12-01

    Full Text Available In this paper, we consider Gauthier’s generalized convolution and then define its binomial analogue as well as alternating binomial analogue. We formulate these convolutions and give some applications of them.

  15. Multivariate Generalizations of the Multiplicative Binomial Distribution: Introducing the MM Package

    OpenAIRE

    Altham, Pat M. E.; Robin K. S. Hankin

    2012-01-01

    We present two natural generalizations of the multinomial and multivariate binomial distributions, which arise from the multiplicative binomial distribution of Altham (1978). The resulting two distributions are discussed and we introduce an R package, MM, which includes associated functionality.

  16. Quality of hurdle treated pork sausages during refrigerated (4 ± 1°C) storage.

    Science.gov (United States)

    Thomas, R; Anjaneyulu, A S R; Kondaiah, N

    2010-06-01

    Pork sausages developed using hurdle technology was evaluated during refrigerated storage (4 ± 1°C). Hurdles incorporated were low pH, low water activity, vacuum packaging and post package reheating. Dipping in potassium sorbate solution prior to vacuum packaging was also tried. Hurdle treatment significantly (p vacuum packaging and reheating inhibited the growth of yeast and molds up to 12 days, while additional dipping of sausages in 1% potassium sorbate solution prior to packaging inhibited their growth even on 30(th) day of storage. Incorporation of hurdles resulted in initial reduction in all the sensory attributes, but they helped to maintain these attributes for significantly longer period compared to control. Hurdle treated sausages exhibited no spoilage signs even on day 30, while the control sausages were found acceptable only up to 18 days.

  17. QUALIFICATION HURDLES AND CHANCES FOR E-MOBILITY

    Directory of Open Access Journals (Sweden)

    Matthias Klumpp

    2014-09-01

    Full Text Available This research contribution aims at describing the crucial role of personnel qualification in logistics as well as in support staff for the use of electric vehicles. The question of “soft process and qualification facts” connected to the use of electric vehicles in the logistics field is explored. Therefore, in a gap analysis based on two empirical studies regarding a comprehensive business knowledge (“Berufswertigkeit” qualification survey in logistics (2012, n = 1.068 as well as an AHP expert interview (2013, n = 40 specific qualification fields and possible hurdles for the use of electric vehicles in logistics are identified and discussed with the help of further expert survey inputs (2014, n = 181. Results show that support processes (recharging, maintenance as well as planning and driving processes (range estimation and control, security issues for commercial electric vehicles require more and different competences than traditional diesel-powered trucks; this poses a major strategic challenge for most transport and logistics companies. Further research lines have to identify specific areas of necessary qualification for electric vehicles in logistics as well as specific target groups (drivers, support staff, maintenance and administration. The operational use of electric vehicles in logistics will strongly depend on the answers to the qualification questions addressed in this paper as has been shown also for the basic cost/investment calculation for electric vehicles.

  18. Hurdling barriers through market uncertainty: Case studies ininnovative technology adoption

    Energy Technology Data Exchange (ETDEWEB)

    Payne, Christopher T.; Radspieler Jr., Anthony; Payne, Jack

    2002-08-18

    The crisis atmosphere surrounding electricity availability in California during the summer of 2001 produced two distinct phenomena in commercial energy consumption decision-making: desires to guarantee energy availability while blackouts were still widely anticipated, and desires to avoid or mitigate significant price increases when higher commercial electricity tariffs took effect. The climate of increased consideration of these factors seems to have led, in some cases, to greater willingness on the part of business decision-makers to consider highly innovative technologies. This paper examines three case studies of innovative technology adoption: retrofit of time-and-temperature signs on an office building; installation of fuel cells to supply power, heating, and cooling to the same building; and installation of a gas-fired heat pump at a microbrewery. We examine the decision process that led to adoption of these technologies. In each case, specific constraints had made more conventional energy-efficient technologies inapplicable. We examine how these barriers to technology adoption developed over time, how the California energy decision-making climate combined with the characteristics of these innovative technologies to overcome the barriers, and what the implications of hurdling these barriers are for future energy decisions within the firms.

  19. Therapeutic Antisense Oligonucleotides against Cancer: Hurdling to the Clinic

    Science.gov (United States)

    Moreno, Pedro; Pêgo, Ana

    2014-10-01

    Under clinical development since the early 90’s and with two successfully approved drugs (Fomivirsen and Mipomersen), oligonucleotide-based therapeutics have not yet delivered a clinical drug to the market in the cancer field. Whilst many pre-clinical data has been generated, a lack of understanding still exists on how to efficiently tackle all the different challenges presented for cancer targeting in a clinical setting. Namely, effective drug vectorization, careful choice of target gene or synergistic multi-gene targeting are surely decisive, while caution must be exerted to avoid potential toxic, often misleading off-target-effects. Here a brief overview will be given on the nucleic acid chemistry advances that established oligonucleotide technologies as a promising therapeutic alternative and ongoing cancer related clinical trials. Special attention will be given towards a perspective on the hurdles encountered specifically in the cancer field by this class of therapeutic oligonucleotides and a view on possible avenues for success is presented, with particular focus on the contribution from nanotechnology to the field.

  20. THERAPEUTIC ANTISENSE OLIGONUCLEOTIDES AGAINST CANCER: HURDLING TO THE CLINIC

    Directory of Open Access Journals (Sweden)

    Pedro Miguel Duarte Moreno

    2014-10-01

    Full Text Available Under clinical development since the early 90’s and with two successfully approved drugs (Fomivirsen and Mipomersen, oligonucleotide-based therapeutics have not yet delivered a clinical drug to the market in the cancer field. Whilst many pre-clinical data has been generated, a lack of understanding still exists on how to efficiently tackle all the different challenges presented for cancer targeting in a clinical setting. Namely, effective drug vectorization, careful choice of target gene or synergistic multi-gene targeting are surely decisive, while caution must be exerted to avoid potential toxic, often misleading off-target-effects. Here a brief overview will be given on the nucleic acid chemistry advances that established oligonucleotide technologies as a promising therapeutic alternative and ongoing cancer related clinical trials. Special attention will be given towards a perspective on the hurdles encountered specifically in the cancer field by this class of therapeutic oligonucleotides and a view on possible avenues for success is presented, with particular focus on the contribution from nanotechnology to the field.

  1. Parallel Binomial American Option Pricing with (and without) Transaction Costs

    CERN Document Server

    Zhang, Nan; Zastawniak, Tomasz

    2011-01-01

    We present a parallel algorithm that computes the ask and bid prices of an American option when proportional transaction costs apply to the trading of the underlying asset. The algorithm computes the prices on recombining binomial trees, and is designed for modern multi-core processors. Although parallel option pricing has been well studied, none of the existing approaches takes transaction costs into consideration. The algorithm that we propose partitions a binomial tree into blocks. In any round of computation a block is further partitioned into regions which are assigned to distinct processors. To minimise load imbalance the assignment of nodes to processors is dynamically adjusted before each new round starts. Synchronisation is required both within a round and between two successive rounds. The parallel speedup of the algorithm is proportional to the number of processors used. The parallel algorithm was implemented in C/C++ via POSIX Threads, and was tested on a machine with 8 processors. In the pricing ...

  2. Binomial Approximations for Barrier Options of Israeli Style

    CERN Document Server

    Dolinsky, Yan

    2009-01-01

    We show that prices and shortfall risks of game (Israeli) barrier options in a sequence of binomial approximations of the Black--Scholes (BS) market converge to the corresponding quantities for similar game barrier options in the BS market with path dependent payoffs and the speed of convergence is estimated, as well. The results are new also for usual American style options and they are interesting from the computational point of view, as well, since in binomial markets these quantities can be obtained via dynamical programming algorithms. The paper continues the study of [11]and [7] but requires substantial additional arguments in view of pecularities of barrier options which, in particular, destroy the regularity of payoffs needed in the above papers.

  3. Central Binomial Sums, Multiple Clausen Values and Zeta Values

    CERN Document Server

    Borwein, J M; Kamnitzer, J

    2000-01-01

    We find and prove relationships between Riemann zeta values and central binomial sums. We also investigate alternating binomial sums (also called Ap\\'ery sums). The study of non-alternating sums leads to an investigation of different types of sums which we call multiple Clausen values. The study of alternating sums leads to a tower of experimental results involving polylogarithms in the golden ratio. In the non-alternating case, there is a strong connection to polylogarithms of the sixth root of unity, encountered in the 3-loop Feynman diagrams of {\\tt hep-th/9803091} and subsequently in hep-ph/9910223, hep-ph/9910224, cond-mat/9911452 and hep-th/0004010.

  4. Determination of finite-difference weights using scaled binomial windows

    KAUST Repository

    Chu, Chunlei

    2012-05-01

    The finite-difference method evaluates a derivative through a weighted summation of function values from neighboring grid nodes. Conventional finite-difference weights can be calculated either from Taylor series expansions or by Lagrange interpolation polynomials. The finite-difference method can be interpreted as a truncated convolutional counterpart of the pseudospectral method in the space domain. For this reason, we also can derive finite-difference operators by truncating the convolution series of the pseudospectral method. Various truncation windows can be employed for this purpose and they result in finite-difference operators with different dispersion properties. We found that there exists two families of scaled binomial windows that can be used to derive conventional finite-difference operators analytically. With a minor change, these scaled binomial windows can also be used to derive optimized finite-difference operators with enhanced dispersion properties. © 2012 Society of Exploration Geophysicists.

  5. Information Loss in Binomial Data Due to Data Compression

    Directory of Open Access Journals (Sweden)

    Susan E. Hodge

    2017-02-01

    Full Text Available This paper explores the idea of information loss through data compression, as occurs in the course of any data analysis, illustrated via detailed consideration of the Binomial distribution. We examine situations where the full sequence of binomial outcomes is retained, situations where only the total number of successes is retained, and in-between situations. We show that a familiar decomposition of the Shannon entropy H can be rewritten as a decomposition into H t o t a l , H l o s t , and H c o m p , or the total, lost and compressed (remaining components, respectively. We relate this new decomposition to Landauer’s principle, and we discuss some implications for the “information-dynamic” theory being developed in connection with our broader program to develop a measure of statistical evidence on a properly calibrated scale.

  6. Exact Group Sequential Methods for Estimating a Binomial Proportion

    Directory of Open Access Journals (Sweden)

    Zhengjia Chen

    2013-01-01

    Full Text Available We first review existing sequential methods for estimating a binomial proportion. Afterward, we propose a new family of group sequential sampling schemes for estimating a binomial proportion with prescribed margin of error and confidence level. In particular, we establish the uniform controllability of coverage probability and the asymptotic optimality for such a family of sampling schemes. Our theoretical results establish the possibility that the parameters of this family of sampling schemes can be determined so that the prescribed level of confidence is guaranteed with little waste of samples. Analytic bounds for the cumulative distribution functions and expectations of sample numbers are derived. Moreover, we discuss the inherent connection of various sampling schemes. Numerical issues are addressed for improving the accuracy and efficiency of computation. Computational experiments are conducted for comparing sampling schemes. Illustrative examples are given for applications in clinical trials.

  7. A distribuição beta binomial negativa

    OpenAIRE

    Madeira, Ana Paula Coelho

    2014-01-01

    Os conceitos de mistura e de distribuições generalizadas são trabalhados. A mistura da distribuição binomial negativa com a distribuição beta é obtida e denominada distribuição beta binomial negativa. A distribuição é unimodal, apresenta super dispersão e não possui todos os momentos. Uma aproximação das equações de log-verossimilhança é encontrada, obtendo-se estimativas dos parâmetros do modelo. Uma validação matemática para o algoritmo de simulação de misturas é apresentado. Como aplicaçõe...

  8. Hits per trial: Basic analysis of binomial data

    Energy Technology Data Exchange (ETDEWEB)

    Atwood, C.L.

    1994-09-01

    This report presents simple statistical methods for analyzing binomial data, such as the number of failures in some number of demands. It gives point estimates, confidence intervals, and Bayesian intervals for the failure probability. It shows how to compare subsets of the data, both graphically and by statistical tests, and how to look for trends in time. It presents a compound model when the failure probability varies randomly. Examples and SAS programs are given.

  9. Factors of binomial sums from the Catalan triangle

    CERN Document Server

    Guo, Victor J W

    2009-01-01

    By using the Newton interpolation formula, we generalize the recent identities on the Catalan triangle obtained by Miana and Romero as well as those of Chen and Chu. We further study divisibility properties of sums of products of binomial coefficients and an odd power of a natural number. For example, we prove that for all positive integers $n_1, ..., n_m$, $n_{m+1}=n_1$, and any nonnegative integer $r$, the expression

  10. Moody's Correlated Binomial Default Distributions for Inhomogeneous Portfolios

    OpenAIRE

    Mori, S.; Kitsukawa, K.; Hisakado, M.

    2006-01-01

    This paper generalizes Moody's correlated binomial default distribution for homogeneous (exchangeable) credit portfolio, which is introduced by Witt, to the case of inhomogeneous portfolios. As inhomogeneous portfolios, we consider two cases. In the first case, we treat a portfolio whose assets have uniform default correlation and non-uniform default probabilities. We obtain the default probability distribution and study the effect of the inhomogeneity on it. The second case corresponds to a ...

  11. Odds Ratios Estimation of Rare Event in Binomial Distribution

    Directory of Open Access Journals (Sweden)

    Kobkun Raweesawat

    2016-01-01

    Full Text Available We introduce the new estimator of odds ratios in rare events using Empirical Bayes method in two independent binomial distributions. We compare the proposed estimates of odds ratios with two estimators, modified maximum likelihood estimator (MMLE and modified median unbiased estimator (MMUE, using the Estimated Relative Error (ERE as a criterion of comparison. It is found that the new estimator is more efficient when compared to the other methods.

  12. Statistical motor number estimation assuming a binomial distribution.

    Science.gov (United States)

    Blok, Joleen H; Visser, Gerhard H; de Graaf, Sándor; Zwarts, Machiel J; Stegeman, Dick F

    2005-02-01

    The statistical method of motor unit number estimation (MUNE) uses the natural stochastic variation in a muscle's compound response to electrical stimulation to obtain an estimate of the number of recruitable motor units. The current method assumes that this variation follows a Poisson distribution. We present an alternative that instead assumes a binomial distribution. Results of computer simulations and of a pilot study on 19 healthy subjects showed that the binomial MUNE values are considerably higher than those of the Poisson method, and in better agreement with the results of other MUNE techniques. In addition, simulation results predict that the performance in patients with severe motor unit loss will be better for the binomial than Poisson method. The adapted method remains closer to physiology, because it can accommodate the increase in activation probability that results from rising stimulus intensity. It does not need recording windows as used with the Poisson method, and is therefore less user-dependent and more objective and quicker in its operation. For these reasons, we believe that the proposed modifications may lead to significant improvements in the statistical MUNE technique.

  13. The Kumaraswamy Binomial Distribution%Kumaraswamy Binomial分布

    Institute of Scientific and Technical Information of China (English)

    李效虎; 黄彦彦; 赵雪艳

    2011-01-01

    The probability of success in a Binomial model is often viewed as a continuous random variable when needs to be considered.In this note,we study the mixed Binomial model with the probability of success having the Kumaraswany distribution.Stochastic orders and dependence in this model are discussed; Further,the new models are employed to fit some real data sets,and the numerical results reveal that KB models perform better than Beta-Binomial model in some occasions.%在Binomial模型中考虑over-dispersion时,每一个独立事件成功的概率通常被视为一个连续随机变量.在本文中,我们提出了成功概率服从Kumaraswamy分布的混合Binomial模型.讨论了这个模型的随机序和相依性;并用数据来拟合这些模型,数值计算结果表明在拟合某些数据时KB模型比BB模型拟合效果更好.

  14. Note on Ward-Horadam H(x) - binomials' recurrences and related interpretations, II

    CERN Document Server

    Kwasniewski, Andrzej Krzysztof

    2011-01-01

    We deliver here second new $\\textit{H(x)}-binomials'$ recurrence formula, were $H(x)-binomials' $ array is appointed by $Ward-Horadam$ sequence of functions which in predominantly considered cases where chosen to be polynomials . Secondly, we supply a review of selected related combinatorial interpretations of generalized binomial coefficients. We then propose also a kind of transfer of interpretation of $p,q-binomial $ coefficients onto $q-binomial$ coefficients interpretations thus bringing us back to $Gy{\\"{o}}rgy P\\'olya $ and Donald Ervin Knuth relevant investigation decades ago.

  15. Low Temperature and Modified Atmosphere: Hurdles for Antibiotic Resistance Transfer?

    Science.gov (United States)

    Van Meervenne, Eva; Van Coillie, Els; Van Weyenberg, Stephanie; Boon, Nico; Herman, Lieve; Devlieghere, Frank

    2015-12-01

    Food is an important dissemination route for antibiotic-resistant bacteria. Factors used during food production and preservation may contribute to the transfer of antibiotic resistance genes, but research on this subject is scarce. In this study, the effect of temperature (7 to 37°C) and modified atmosphere packaging (air, 50% CO2-50% N2, and 100% N2) on antibiotic resistance transfer from Lactobacillus sakei subsp. sakei to Listeria monocytogenes was evaluated. Filter mating was performed on nonselective agar plates with high-density inocula. A more realistic setup was created by performing modified atmosphere experiments on cooked ham using high-density and low-density inocula. Plasmid transfer was observed between 10 and 37°C, with plasmid transfer also observed at 7°C during a prolonged incubation period. When high-density inocula were used, transconjugants were detected, both on agar plates and cooked ham, under the three atmospheres (air, 50% CO2-50% N2, and 100% N2) at 7°C. This yielded a median transfer ratio (number of transconjugants/number of recipients) with an order of magnitude of 10(-4) to 10(-6). With low-density inocula, transfer was only detected under the 100% N2 atmosphere after 10-day incubation at 7°C, yielding a transfer ratio of 10(-5). Under this condition, the highest bacterial density was obtained. The results indicate that low temperature and modified atmosphere packaging, two important hurdles in the food industry, do not necessarily prevent plasmid transfer from Lactobacillus sakei subsp. sakei to Listeria monocytogenes.

  16. Binomial coefficient-harmonic sum identities associated to supercongruences

    CERN Document Server

    McCarthy, Dermot

    2012-01-01

    We establish two binomial coefficient--generalized harmonic sum identities using the partial fraction decomposition method. These identities are a key ingredient in the proofs of numerous supercongruences. In particular, in other works of the author, they are used to establish modulo $p^k$ ($k>1$) congruences between truncated generalized hypergeometric series, and a function which extends Greene's hypergeometric function over finite fields to the $p$-adic setting. A specialization of one of these congruences is used to prove an outstanding conjecture of Rodriguez-Villegas which relates a truncated generalized hypergeometric series to the $p$-th Fourier coefficient of a particular modular form.

  17. Representaciones de la distribución de probabilidad binomial

    OpenAIRE

    Alvarado, Hugo; Retamal, María Lidia

    2014-01-01

    El currículo de estadística en el sistema escolar sugiere desde la infancia un cambio metodológico de enseñanza hacia el desarrollo de los aspectos intuitivos de lo estocástico en situaciones de incertidumbre. El Taller tiene dos propósitos, presentar actividades de experimentos aleatorios con dispositivos manipulativos, algebraico y computacional para familiarizarse con la noción de distribución de probabilidad binomial. También, ilustrar que su enseñanza en la educación secundaria por me...

  18. Representaciones de la distribución de probabilidad binomial

    OpenAIRE

    Alvarado, Hugo; Retamal, María Lidia

    2014-01-01

    El currículo de estadística en el sistema escolar sugiere desde la infancia un cambio metodológico de enseñanza hacia el desarrollo de los aspectos intuitivos de lo estocástico en situaciones de incertidumbre. El Taller tiene dos propósitos, presentar actividades de experimentos aleatorios con dispositivos manipulativos, algebraico y computacional para familiarizarse con la noción de distribución de probabilidad binomial. También, ilustrar que su enseñanza en la educación secundaria por me...

  19. Using the beta-binomial distribution to characterize forest health

    Energy Technology Data Exchange (ETDEWEB)

    Zarnoch, S.J.; Anderson, R.L.; Sheffield, R.M.

    1995-12-31

    The beta-binomial distribution is suggested as a model for describing and analyzing the dichotomous data obtained from programs monitoring the health of forests in the United States. Maximum likelihood estimation of the parameters is given as well as asymptotic likelihood ratio tests. The procedure is illustrated with data on dogwood anthracnose infection (caused by Discula destructiva) in the southeastern United States. The parameters estimates have important biological interpretation, and tests of hypotheses are more meaningful than traditional statistical analyses. The value of a modeling approach to dichotomous data analysis is emphasized.

  20. Binomial Distribution Sample Confidence Intervals Estimation 6. Excess Risk

    Directory of Open Access Journals (Sweden)

    Sorana BOLBOACĂ

    2004-02-01

    Full Text Available We present the problem of the confidence interval estimation for excess risk (Y/n-X/m fraction, a parameter which allows evaluating of the specificity of an association between predisposing or causal factors and disease in medical studies. The parameter is computes based on 2x2 contingency table and qualitative variables. The aim of this paper is to introduce four new methods of computing confidence intervals for excess risk called DAC, DAs, DAsC, DBinomial, and DBinomialC and to compare theirs performance with the asymptotic method called here DWald.In order to assess the methods, we use the PHP programming language and a PHP program was creates. The performance of each method for different sample sizes and different values of binomial variables were assess using a set of criterions. First, the upper and lower boundaries for a given X, Y and a specified sample size for choused methods were compute. Second, were assessed the average and standard deviation of the experimental errors, and the deviation relative to imposed significance level α = 5%. Four methods were assessed on random numbers for binomial variables and for sample sizes from 4 to 1000 domain.The experiments show that the DAC methods obtain performances in confidence intervals estimation for excess risk.

  1. Generalized binomial multiplicative cascade processes and asymmetrical multifractal distributions

    Science.gov (United States)

    Cheng, Q.

    2014-04-01

    The concepts and models of multifractals have been employed in various fields in the geosciences to characterize singular fields caused by nonlinear geoprocesses. Several indices involved in multifractal models, i.e., asymmetry, multifractality, and range of singularity, are commonly used to characterize nonlinear properties of multifractal fields. An understanding of how these indices are related to the processes involved in the generation of multifractal fields is essential for multifractal modeling. In this paper, a five-parameter binomial multiplicative cascade model is proposed based on the anisotropic partition processes. Each partition divides the unit set (1-D length or 2-D area) into h equal subsets (segments or subareas) and m1 of them receive d1 (> 0) and m2 receive d2 (> 0) proportion of the mass in the previous subset, respectively, where m1+m2 ≤ h. The model is demonstrated via several examples published in the literature with asymmetrical fractal dimension spectra. This model demonstrates the various properties of asymmetrical multifractal distributions and multifractal indices with explicit functions, thus providing insight into and an understanding of the properties of asymmetrical binomial multifractal distributions.

  2. Ray trajectories, binomial of a new type, and the binary system

    CERN Document Server

    Yurkin, Alexander V

    2013-01-01

    The paper describes a new algorithm of construction of the nonlinear arithmetic triangle on the basis of numerical simulation and the binary system. It demonstrates that the numbers that fill the nonlinear arithmetic triangle may be binomial coefficients of a new type. An analogy has been drawn with the binomial coefficients calculated with the use of the Pascal triangle. The paper provides a geometrical interpretation of binomials of different types in considering the branching systems of rays.

  3. Covering Resilience: A Recent Development for Binomial Checkpointing

    Energy Technology Data Exchange (ETDEWEB)

    Walther, Andrea; Narayanan, Sri Hari Krishna

    2016-09-12

    In terms of computing time, adjoint methods offer a very attractive alternative to compute gradient information, required, e.g., for optimization purposes. However, together with this very favorable temporal complexity result comes a memory requirement that is in essence proportional with the operation count of the underlying function, e.g., if algorithmic differentiation is used to provide the adjoints. For this reason, checkpointing approaches in many variants have become popular. This paper analyzes an extension of the so-called binomial approach to cover also possible failures of the computing systems. Such a measure of precaution is of special interest for massive parallel simulations and adjoint calculations where the mean time between failure of the large scale computing system is smaller than the time needed to complete the calculation of the adjoint information. We describe the extensions of standard checkpointing approaches required for such resilience, provide a corresponding implementation and discuss first numerical results.

  4. The prime factors of Wendt's binomial circulant determinant

    Science.gov (United States)

    Fee, Greg; Granville, Andrew

    1991-10-01

    Wendt's binomial circulant determinant, {W_m} , is the determinant of an m by m circulant matrix of integers, with (i, j)th entry ( {begin{array}{*{20}{c}} m {\\vert i - j\\vert} } ) whenever 2 divides m but 3 does not. We explain how we found the prime factors of {W_m} for each even m ≤ 200 by implementing a new method for computations in algebraic number fields that uses only modular arithmetic. As a consequence we prove that if p and q = mp + 1 are odd primes, 3 does not divide m, and m ≤ 200 , then the first case of Fermat's Last Theorem is true for exponent p.

  5. Transforming Recurrent Sequences by Using the Binomial and Invert Operators

    CERN Document Server

    Barbero, Stefano; Murru, Nadir

    2011-01-01

    In this paper we study the action of the Binomial and Invert (interpolated) operators on the set of linear recurrent sequences. We prove that these operators preserve this set, and we determine how they change the characteristic polynomials. We show that these operators, with the aid of two other elementary operators (essentially the left and right shifts), can transform any impulse sequence (a linear recurrent sequence starting from $(0,...,0,1)$) into any other impulse sequence, by two processes that we call \\emph{construction} and \\emph{deconstruction}. Finally, we give some applications to polynomial sequences and pyramidal numbers. We also find a new identity on Fibonacci numbers, and we prove that $r$--bonacci numbers are a Bell polynomial transform of the $(r-1)$--bonacci numbers.

  6. Low reheating temperatures in monomial and binomial inflationary models

    Energy Technology Data Exchange (ETDEWEB)

    Rehagen, Thomas; Gelmini, Graciela B. [Department of Physics and Astronomy, UCLA,475 Portola Plaza, Los Angeles, CA 90095 (United States)

    2015-06-23

    We investigate the allowed range of reheating temperature values in light of the Planck 2015 results and the recent joint analysis of Cosmic Microwave Background (CMB) data from the BICEP2/Keck Array and Planck experiments, using monomial and binomial inflationary potentials. While the well studied ϕ{sup 2} inflationary potential is no longer favored by current CMB data, as well as ϕ{sup p} with p>2, a ϕ{sup 1} potential and canonical reheating (w{sub re}=0) provide a good fit to the CMB measurements. In this last case, we find that the Planck 2015 68% confidence limit upper bound on the spectral index, n{sub s}, implies an upper bound on the reheating temperature of T{sub re}≲6×10{sup 10} GeV, and excludes instantaneous reheating. The low reheating temperatures allowed by this model open the possibility that dark matter could be produced during the reheating period instead of when the Universe is radiation dominated, which could lead to very different predictions for the relic density and momentum distribution of WIMPs, sterile neutrinos, and axions. We also study binomial inflationary potentials and show the effects of a small departure from a ϕ{sup 1} potential. We find that as a subdominant ϕ{sup 2} term in the potential increases, first instantaneous reheating becomes allowed, and then the lowest possible reheating temperature of T{sub re}=4 MeV is excluded by the Planck 2015 68% confidence limit.

  7. Gene Editing of Human Hematopoietic Stem and Progenitor Cells: Promise and Potential Hurdles.

    Science.gov (United States)

    Yu, Kyung-Rok; Natanson, Hannah; Dunbar, Cynthia E

    2016-08-02

    Hematopoietic stem and progenitor cells (HSPCs) have great therapeutic potential because of their ability to both self-renew and differentiate. It has been proposed that, given their unique properties, a small number of genetically modified HSPCs could accomplish lifelong, corrective reconstitution of the entire hematopoietic system in patients with various hematologic disorders. Scientists have demonstrated that gene addition therapies-targeted to HSPCs and using integrating retroviral vectors-possess clear clinical benefits in multiple diseases, among them immunodeficiencies, storage disorders, and hemoglobinopathies. Scientists attempting to develop clinically relevant gene therapy protocols have, however, encountered a number of unexpected hurdles because of their incomplete knowledge of target cells, genomic control, and gene transfer technologies. Targeted gene-editing technologies using engineered nucleases such as ZFN, TALEN, and/or CRISPR/Cas9 RGEN show great clinical promise, allowing for the site-specific correction of disease-causing mutations-a process with important applications in autosomal dominant or dominant-negative genetic disorders. The relative simplicity of the CRISPR/Cas9 system, in particular, has sparked an exponential increase in the scientific community's interest in and use of these gene-editing technologies. In this minireview, we discuss the specific applications of gene-editing technologies in human HSPCs, as informed by prior experience with gene addition strategies. HSPCs are desirable but challenging targets; the specific mechanisms these cells evolved to protect themselves from DNA damage render them potentially more susceptible to oncogenesis, especially given their ability to self-renew and their long-term proliferative potential. We further review scientists' experience with gene-editing technologies to date, focusing on strategies to move these techniques toward implementation in safe and effective clinical trials.

  8. On some binomial coefficients related to the evaluation of tan(nx)

    CERN Document Server

    Ma, Shi-Mei

    2012-01-01

    The purpose of this paper is to study some binomial coefficients which are related to the evaluation of tan(nx). We mainly present a connection between these binomial coefficients and the coefficients of a family of derivative polynomials for tangent and secant.

  9. Saddlepoint approximations for the sum of independent non-identically distributed binomial random variables

    NARCIS (Netherlands)

    Eisinga, R.N.; Grotenhuis, H.F. te; Pelzer, B.J.

    2013-01-01

    We discuss saddlepoint approximations to the distribution of the sum of independent non-identically distributed binomial random variables. We examine the accuracy of the saddlepoint methods for a sum of 10 binomials with different sets of parameter values. The numerical results indicate that the sad

  10. Interval estimation of binomial proportion in clinical trials with a two-stage design.

    Science.gov (United States)

    Tsai, Wei-Yann; Chi, Yunchan; Chen, Chia-Min

    2008-01-15

    Generally, a two-stage design is employed in Phase II clinical trials to avoid giving patients an ineffective drug. If the number of patients with significant improvement, which is a binomial response, is greater than a pre-specified value at the first stage, then another binomial response at the second stage is also observed. This paper considers interval estimation of the response probability when the second stage is allowed to continue. Two asymptotic interval estimators, Wald and score, as well as two exact interval estimators, Clopper-Pearson and Sterne, are constructed according to the two binomial responses from this two-stage design, where the binomial response at the first stage follows a truncated binomial distribution. The mean actual coverage probability and expected interval width are employed to evaluate the performance of these interval estimators. According to the comparison results, the score interval is recommended for both Simon's optimal and minimax designs.

  11. An efficient binomial model-based measure for sequence comparison and its application.

    Science.gov (United States)

    Liu, Xiaoqing; Dai, Qi; Li, Lihua; He, Zerong

    2011-04-01

    Sequence comparison is one of the major tasks in bioinformatics, which could serve as evidence of structural and functional conservation, as well as of evolutionary relations. There are several similarity/dissimilarity measures for sequence comparison, but challenges remains. This paper presented a binomial model-based measure to analyze biological sequences. With help of a random indicator, the occurrence of a word at any position of sequence can be regarded as a random Bernoulli variable, and the distribution of a sum of the word occurrence is well known to be a binomial one. By using a recursive formula, we computed the binomial probability of the word count and proposed a binomial model-based measure based on the relative entropy. The proposed measure was tested by extensive experiments including classification of HEV genotypes and phylogenetic analysis, and further compared with alignment-based and alignment-free measures. The results demonstrate that the proposed measure based on binomial model is more efficient.

  12. A comparison of observation-level random effect and Beta-Binomial models for modelling overdispersion in Binomial data in ecology & evolution

    Directory of Open Access Journals (Sweden)

    Xavier A. Harrison

    2015-07-01

    Full Text Available Overdispersion is a common feature of models of biological data, but researchers often fail to model the excess variation driving the overdispersion, resulting in biased parameter estimates and standard errors. Quantifying and modeling overdispersion when it is present is therefore critical for robust biological inference. One means to account for overdispersion is to add an observation-level random effect (OLRE to a model, where each data point receives a unique level of a random effect that can absorb the extra-parametric variation in the data. Although some studies have investigated the utility of OLRE to model overdispersion in Poisson count data, studies doing so for Binomial proportion data are scarce. Here I use a simulation approach to investigate the ability of both OLRE models and Beta-Binomial models to recover unbiased parameter estimates in mixed effects models of Binomial data under various degrees of overdispersion. In addition, as ecologists often fit random intercept terms to models when the random effect sample size is low (<5 levels, I investigate the performance of both model types under a range of random effect sample sizes when overdispersion is present. Simulation results revealed that the efficacy of OLRE depends on the process that generated the overdispersion; OLRE failed to cope with overdispersion generated from a Beta-Binomial mixture model, leading to biased slope and intercept estimates, but performed well for overdispersion generated by adding random noise to the linear predictor. Comparison of parameter estimates from an OLRE model with those from its corresponding Beta-Binomial model readily identified when OLRE were performing poorly due to disagreement between effect sizes, and this strategy should be employed whenever OLRE are used for Binomial data to assess their reliability. Beta-Binomial models performed well across all contexts, but showed a tendency to underestimate effect sizes when modelling non-Beta-Binomial

  13. Modelling alcohol consumption during adolescence using zero inflated negative binomial and decision trees

    Directory of Open Access Journals (Sweden)

    Alfonso Palmer

    2010-07-01

    Full Text Available Alcohol is currently the most consumed substance among the Spanish adolescent population. Some of the variables that bear an influence on this consumption include ease of access, use of alcohol by friends and some personality factors. The aim of this study was to analyze and quantify the predictive value of these variables specifically on alcohol consumption in the adolescent population. The useful sample was made up of 6,145 adolescents (49.8% boys and 50.2% girls with a mean age of 15.4 years (SE= 1.2. The data were analyzed using the statistical model for a count variable and Data Mining techniques. The results show the influence of ease of access, alcohol consumption by the group of friends, and certain personality factors on alcohol intake, allowing us to quantify the intensity of this influence according to age and gender. Knowing these factors is the starting point in elaborating specific preventive actions against alcohol consumption.

  14. On the multiplicity distribution in statistical model: (I) negative binomial distribution

    CERN Document Server

    Xu, Hao-jie

    2016-01-01

    With the distribution of principal thermodynamic variables (e.g.,volume) and the probability condition from reference multiplicity, we develop an improved baseline measure for multiplicity distribution in statistical model to replace the traditional Poisson expectations. We demonstrate the mismatches between experimental measurements and previous theoretical calculations on multiplicity distributions. We derive a general expression for multiplicity distribution, i.e. a conditional probability distribution, in statistical model and calculate its cumulants under Poisson approximation in connection with recent data for multiplicity fluctuations. We find that probability condition from reference multiplicity are crucial to explain the centrality resolution effect in experiment. With the improved baseline measure for multiplicity distribution, we can quantitatively reproduce the cumulants (cumulant products) for multiplicity distribution of total (net) charges measured in experiments.

  15. Hurdles overcome in technology transfer for AIET and Positive outcome in Indian patients

    Directory of Open Access Journals (Sweden)

    Dedeepiya V

    2012-01-01

    Full Text Available Introduction Cell based immunotherapies have been in practice in Japan for the past two decades with established clinical trials on its efficacy in both solid tumours and hematological malignancies including gastric cancer, ovarian cancer , lung cancer and liver cancer. [1,2,3,4] In India, NCRM has been providing Autologous Immune Enhancement Therapy (AIET using autologous Natural Killer (NK cells and activated T Lymphocytes for Cancer since 2005 following the established protocols practiced by the Biotherapy Institute of Japan. Significant outcome achieved after AIET in advanced pancreatic cancer, Acute Myeloid leukemia (AML in Indian patients have already been reported. [5, 6] Here we report our experience in few more patients and present the hurdles overcome and lessons learned in translating the technology from Japan to India Case Details: Case 1: A 54 year-old female presented with Stage IV recurrent ovarian malignancy in 2010 with a history of previous surgery and chemotherapy for ovarian malignancy in June 2009. The CA-125 level of 243 U/ml. CT scan revealed lesions in the liver, spleen, along the greater curvature of body of stomach and in the perisplenic region, between the medial aspect of liver and stomach and in the right inguinal region. She was suggested six cycles of chemotherapy with Doxorubicin (50 mg and Carboplatin (450 mg along with AIET. After proper informed consent, the peripheral blood was withdrawn and the in vitro expansion of the NK cells, activated T Lymphocytes from the peripheral blood was performed using the protocol reported earlier. [7] Average cell count after the in vitro expansion was 1.2 X 108 cells. Six transfusions of the in vitro expanded NK cells and activated T lymphocytes were administered following which the CA-125 decreased to 4.7 U/mL. CT scan taken in December 2010 showed a regression of the lesions in the spleen and perisplenic peritoneal deposits, stable hepatic lesions and resolution of

  16. Exploring Public Perception of Paratransit Service Using Binomial Logistic Regression

    Directory of Open Access Journals (Sweden)

    Hisashi Kubota

    2007-01-01

    Full Text Available Knowledge of the market is a requirement for a successful provision of public transportation. This study aims to explore public perception of paratransit service, as represented by the user and non-user of paratransit. The analysis has been conducted based on the public’s response, by creating several binomial logistic regression models using the public perception of the quality of service, quality of car, quality of driver, and fare. These models illustrate the characteristics and important variables to establish whether the public will use more paratransit in the future once improvements will have been made. Moreover, several models are developed to explore public perception in order to find out whether they agree to the replacement of paratransit with other types of transportation modes. All models are well fitting. These models are able to explain the respondents’ characteristics and to reveal their actual perception of the operation of paratransit. This study provides a useful tool to know the market in greater depth.

  17. Microbial comparative pan-genomics using binomial mixture models

    Directory of Open Access Journals (Sweden)

    Ussery David W

    2009-08-01

    Full Text Available Abstract Background The size of the core- and pan-genome of bacterial species is a topic of increasing interest due to the growing number of sequenced prokaryote genomes, many from the same species. Attempts to estimate these quantities have been made, using regression methods or mixture models. We extend the latter approach by using statistical ideas developed for capture-recapture problems in ecology and epidemiology. Results We estimate core- and pan-genome sizes for 16 different bacterial species. The results reveal a complex dependency structure for most species, manifested as heterogeneous detection probabilities. Estimated pan-genome sizes range from small (around 2600 gene families in Buchnera aphidicola to large (around 43000 gene families in Escherichia coli. Results for Echerichia coli show that as more data become available, a larger diversity is estimated, indicating an extensive pool of rarely occurring genes in the population. Conclusion Analyzing pan-genomics data with binomial mixture models is a way to handle dependencies between genomes, which we find is always present. A bottleneck in the estimation procedure is the annotation of rarely occurring genes.

  18. Low reheating temperatures in monomial and binomial inflationary potentials

    CERN Document Server

    Rehagen, Thomas

    2015-01-01

    We investigate the allowed range of reheating temperature values in light of the Planck 2015 results and the recent joint analysis of Cosmic Microwave Background (CMB) data from the BICEP2/Keck Array and Planck experiments, using monomial and binomial inflationary potentials. While the well studied $\\phi^2$ inflationary potential is no longer favored by current CMB data, as well as $\\phi^p$ with $p>2$, a $\\phi^1$ potential and canonical reheating ($w_{re}=0$) provide a good fit to the CMB measurements. In this last case, we find that the Planck 2015 $68\\%$ confidence limit upper bound on the spectral index, $n_s$, implies an upper bound on the reheating temperature of $T_{re}\\lesssim 6\\times 10^{10}\\,{\\rm GeV}$, and excludes instantaneous reheating. The low reheating temperatures allowed by this model open the possiblity that dark matter could be produced during the reheating period instead of when the Universe is radiation dominated, which could lead to very different predictions for the relic density and mo...

  19. Meta-analysis of studies with bivariate binary outcomes: a marginal beta-binomial model approach.

    Science.gov (United States)

    Chen, Yong; Hong, Chuan; Ning, Yang; Su, Xiao

    2016-01-15

    When conducting a meta-analysis of studies with bivariate binary outcomes, challenges arise when the within-study correlation and between-study heterogeneity should be taken into account. In this paper, we propose a marginal beta-binomial model for the meta-analysis of studies with binary outcomes. This model is based on the composite likelihood approach and has several attractive features compared with the existing models such as bivariate generalized linear mixed model (Chu and Cole, 2006) and Sarmanov beta-binomial model (Chen et al., 2012). The advantages of the proposed marginal model include modeling the probabilities in the original scale, not requiring any transformation of probabilities or any link function, having closed-form expression of likelihood function, and no constraints on the correlation parameter. More importantly, because the marginal beta-binomial model is only based on the marginal distributions, it does not suffer from potential misspecification of the joint distribution of bivariate study-specific probabilities. Such misspecification is difficult to detect and can lead to biased inference using currents methods. We compare the performance of the marginal beta-binomial model with the bivariate generalized linear mixed model and the Sarmanov beta-binomial model by simulation studies. Interestingly, the results show that the marginal beta-binomial model performs better than the Sarmanov beta-binomial model, whether or not the true model is Sarmanov beta-binomial, and the marginal beta-binomial model is more robust than the bivariate generalized linear mixed model under model misspecifications. Two meta-analyses of diagnostic accuracy studies and a meta-analysis of case-control studies are conducted for illustration.

  20. A general binomial regression model to estimate standardized risk differences from binary response data.

    Science.gov (United States)

    Kovalchik, Stephanie A; Varadhan, Ravi; Fetterman, Barbara; Poitras, Nancy E; Wacholder, Sholom; Katki, Hormuzd A

    2013-02-28

    Estimates of absolute risks and risk differences are necessary for evaluating the clinical and population impact of biomedical research findings. We have developed a linear-expit regression model (LEXPIT) to incorporate linear and nonlinear risk effects to estimate absolute risk from studies of a binary outcome. The LEXPIT is a generalization of both the binomial linear and logistic regression models. The coefficients of the LEXPIT linear terms estimate adjusted risk differences, whereas the exponentiated nonlinear terms estimate residual odds ratios. The LEXPIT could be particularly useful for epidemiological studies of risk association, where adjustment for multiple confounding variables is common. We present a constrained maximum likelihood estimation algorithm that ensures the feasibility of risk estimates of the LEXPIT model and describe procedures for defining the feasible region of the parameter space, judging convergence, and evaluating boundary cases. Simulations demonstrate that the methodology is computationally robust and yields feasible, consistent estimators. We applied the LEXPIT model to estimate the absolute 5-year risk of cervical precancer or cancer associated with different Pap and human papillomavirus test results in 167,171 women undergoing screening at Kaiser Permanente Northern California. The LEXPIT model found an increased risk due to abnormal Pap test in human papillomavirus-negative that was not detected with logistic regression. Our R package blm provides free and easy-to-use software for fitting the LEXPIT model.

  1. A Binomial Mixture Model for Classification Performance: A Commentary on Waxman, Chambers, Yntema, and Gelman (1989).

    Science.gov (United States)

    Thomas, Hoben

    1989-01-01

    Individual differences in children's performance on a classification task are modeled by a two component binomial mixture distribution. The model accounts for data well, with variance accounted for ranging from 87 to 95 percent. (RJC)

  2. Empirical Bayes Estimates of Domain Scores under Binomial and Hypergeometric Distributions for Test Scores.

    Science.gov (United States)

    Lin, Miao-Hsiang; Hsiung, Chao A.

    1994-01-01

    Two simple empirical approximate Bayes estimators are introduced for estimating domain scores under binomial and hypergeometric distributions respectively. Criteria are established regarding use of these functions over maximum likelihood estimation counterparts. (SLD)

  3. Biomechanical study athletes’ movement techniques in the hurdles (on example of phase of flight

    Directory of Open Access Journals (Sweden)

    Adashevskiy V.M.

    2014-07-01

    Full Text Available Purpose: To design a theoretical biomechanical model of athletes’ movement techniques in the hurdles and then check there movements on real athletes. Material : In the practical part of the study participated 10 smortsmen. Results : Showing the possibility of constructing a theoretical model of hurdling technique. The basis of constructing a model using the known approaches in theoretical mechanics. Shows the calculated and actual performance movement of the athlete. Conclusions : The developed model provides a good theoretical understanding of the interactions of individual elements of movement and the ability to simulate different situations and to determine the optimal values of the kinematic and dynamic characteristics of the movement of the athlete. The model allows the individual elements of motion correction directly in the process of training. When analyzing art movement should consider specific features of physical development and anthropometric characteristics of the athlete's body.

  4. Solid anaerobic digestion: State-of-art, scientific and technological hurdles.

    Science.gov (United States)

    André, Laura; Pauss, André; Ribeiro, Thierry

    2017-09-05

    In this paper, a state-of-art about solid anaerobic digestion (AD), focused on recent progress and trends of research is proposed. Solid anaerobic digestion should be the most appropriate process for degradation of by-products with high total solid (TS) content, especially lignocellulosic materials like agricultural waste (straw, manure), household waste and food waste. Solid AD is already widely used in waste water treatment plant for treating plant for sewage sludge but could be more developed for lignocellulosic materials with high TS content. Many research works were carried out in Europe on solid AD, focused on current hurdles (BMP, codigestion, inhibition, microbial population, rheology, water transfers, inoculum, etc.) in order to optimize the solid AD process. In conclusion, hurdles of solid AD process should and must be solved in order to propose better productivity and profitability of such system operating with high TS content (>15%), favouring reliable industrial processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Process intensification in the petrochemicals industry: Drivers and hurdles for commercial implementation

    OpenAIRE

    Harmsen, Jan

    2010-01-01

    The process intensification technologies, reactive distillation, dividing wall column distillation (DWC) and reverse flow reactors (RFR) have been implemented at commercial scale in the petrochemical industry each more than 100 times. These technologies have been analysed with four drivers for innovation in the chemical process industry: feedstock cost reduction, capital expenditure reduction, energy reduction and safety risk reduction and with four hurdles for innovation: risk of failure by ...

  6. Double-Hurdle Model of Fresh Fish Consumption among Urban Households in South-West Nigeria

    Directory of Open Access Journals (Sweden)

    S.O. Akinbode

    2012-11-01

    Full Text Available Most studies on consumption of products with possibility of observing zero-consumption for some consumers have modeled consumption function using the Tobit model, assuming that factors that are responsible for whether to consume a product or not are equally responsible for determining how much to consume. This approach has been severally faulted. This study investigated factors affecting consumption of fresh fish using the single step estimation method of the Tobit model, the independent double-hurdle approach and the dependent double-hurdle model. Data collected from 218 households in Abeokuta, South-west Nigeria were used for the study. Model fitness criteria revealed the superiority of joint estimation (dependent double-hurdle model. The model results revealed that husband’s income, wife’s income, expenditure on beef and dependency ratio significantly affected participation (decision to consume while household size, husband’s education, husband’s income, wife’s income, expenditure on dry fish and dependency ratio significantly affected consumption (how much to consume. It is recommended that public enlightenment should focus on the importance of consuming fresh fish among households and fresh fish sellers should focus on educated and high income households as this segment of the market demand more of the product.

  7. Total Quality Management in Higher Education: Clearing the Hurdles. A Survey on Strategies for Implementing Quality Management Practices in Higher Education. A GOAL/QPC Application Report.

    Science.gov (United States)

    Seymour, Daniel

    Based on a survey of Quality Management (QM) practitioners at 21 colleges, this study presents the 10 most difficult implementation hurdles to QM in higher education and a set of hurdle-clearing strategies. The hurdles are: (1) lack of time to implement QM; (2) perception that QM is something for janitorial and housing staffs but not applicable to…

  8. Total Quality Management in Higher Education: Clearing the Hurdles. A Survey on Strategies for Implementing Quality Management Practices in Higher Education. A GOAL/QPC Application Report.

    Science.gov (United States)

    Seymour, Daniel

    Based on a survey of Quality Management (QM) practitioners at 21 colleges, this study presents the 10 most difficult implementation hurdles to QM in higher education and a set of hurdle-clearing strategies. The hurdles are: (1) lack of time to implement QM; (2) perception that QM is something for janitorial and housing staffs but not applicable to…

  9. Binomial Distribution Sample Confidence Intervals Estimation 1. Sampling and Medical Key Parameters Calculation

    Directory of Open Access Journals (Sweden)

    Tudor DRUGAN

    2003-08-01

    Full Text Available The aim of the paper was to present the usefulness of the binomial distribution in studying of the contingency tables and the problems of approximation to normality of binomial distribution (the limits, advantages, and disadvantages. The classification of the medical keys parameters reported in medical literature and expressing them using the contingency table units based on their mathematical expressions restrict the discussion of the confidence intervals from 34 parameters to 9 mathematical expressions. The problem of obtaining different information starting with the computed confidence interval for a specified method, information like confidence intervals boundaries, percentages of the experimental errors, the standard deviation of the experimental errors and the deviation relative to significance level was solves through implementation in PHP programming language of original algorithms. The cases of expression, which contain two binomial variables, were separately treated. An original method of computing the confidence interval for the case of two-variable expression was proposed and implemented. The graphical representation of the expression of two binomial variables for which the variation domain of one of the variable depend on the other variable was a real problem because the most of the software used interpolation in graphical representation and the surface maps were quadratic instead of triangular. Based on an original algorithm, a module was implements in PHP in order to represent graphically the triangular surface plots. All the implementation described above was uses in computing the confidence intervals and estimating their performance for binomial distributions sample sizes and variable.

  10. The three hurdles of tax planning: How business context, aims of tax planning, and tax manager power affect tax

    OpenAIRE

    Feller, Anna; Schanz, Deborah

    2014-01-01

    The question of why some companies pay more taxes than others is a widely investigated topic of interest. One of the famous suspect explanations is a phenomenon called tax avoidance. We develop a holistic theoretical concept of influences on corporate tax planning through a series of 19 in-depth German tax expert interviews. Our findings show that three distinct hurdles in the tax planning process can explain different levels of tax expense across companies. Those three hurdles are which tax ...

  11. Possibility and Challenges of Conversion of Current Virus Species Names to Linnaean Binomials

    Energy Technology Data Exchange (ETDEWEB)

    Postler, Thomas S.; Clawson, Anna N.; Amarasinghe, Gaya K.; Basler, Christopher F.; Bavari, Sbina; Benkő, Mária; Blasdell, Kim R.; Briese, Thomas; Buchmeier, Michael J.; Bukreyev, Alexander; Calisher, Charles H.; Chandran, Kartik; Charrel, Rémi; Clegg, Christopher S.; Collins, Peter L.; Juan Carlos, De La Torre; Derisi, Joseph L.; Dietzgen, Ralf G.; Dolnik, Olga; Dürrwald, Ralf; Dye, John M.; Easton, Andrew J.; Emonet, Sébastian; Formenty, Pierre; Fouchier, Ron A. M.; Ghedin, Elodie; Gonzalez, Jean-Paul; Harrach, Balázs; Hewson, Roger; Horie, Masayuki; Jiāng, Dàohóng; Kobinger, Gary; Kondo, Hideki; Kropinski, Andrew M.; Krupovic, Mart; Kurath, Gael; Lamb, Robert A.; Leroy, Eric M.; Lukashevich, Igor S.; Maisner, Andrea; Mushegian, Arcady R.; Netesov, Sergey V.; Nowotny, Norbert; Patterson, Jean L.; Payne, Susan L.; PaWeska, Janusz T.; Peters, Clarence J.; Radoshitzky, Sheli R.; Rima, Bertus K.; Romanowski, Victor; Rubbenstroth, Dennis; Sabanadzovic, Sead; Sanfaçon, Hélène; Salvato, Maria S.; Schwemmle, Martin; Smither, Sophie J.; Stenglein, Mark D.; Stone, David M.; Takada, Ayato; Tesh, Robert B.; Tomonaga, Keizo; Tordo, Noël; Towner, Jonathan S.; Vasilakis, Nikos; Volchkov, Viktor E.; Wahl-Jensen, Victoria; Walker, Peter J.; Wang, Lin-Fa; Varsani, Arvind; Whitfield, Anna E.; Zerbini, F. Murilo; Kuhn, Jens H.

    2016-10-22

    Botanical, mycological, zoological, and prokaryotic species names follow the Linnaean format, consisting of an italicized Latinized binomen with a capitalized genus name and a lower case species epithet (e.g., Homo sapiens). Virus species names, however, do not follow a uniform format, and, even when binomial, are not Linnaean in style. In this thought exercise, we attempted to convert all currently official names of species included in the virus family Arenaviridae and the virus order Mononegavirales to Linnaean binomials, and to identify and address associated challenges and concerns. Surprisingly, this endeavor was not as complicated or time-consuming as even the authors of this article expected when conceiving the experiment. [Arenaviridae; binomials; ICTV; International Committee on Taxonomy of Viruses; Mononegavirales; virus nomenclature; virus taxonomy.

  12. A double-hurdle model estimation of cocoa farmers' willingness to pay for crop insurance in Ghana.

    Science.gov (United States)

    Okoffo, Elvis Dartey; Denkyirah, Elisha Kwaku; Adu, Derick Taylor; Fosu-Mensah, Benedicta Yayra

    2016-01-01

    Agriculture is an important sector in Ghana's economy, however, with high risk due to natural factors like climate change, pests and diseases and bush fires among others. Farmers in the Brong-Ahafo region of Ghana which is known as one of the major cocoa producing regions, face these risks which sometimes results in crop failure. The need for farmers to therefore insure their farms against crop loss is crucial. Insurance has been a measure to guard against risk. The aim of this study was to assess cocoa farmers' willingness to access crop insurance, the factors affecting willingness to pay (WTP) for crop insurance scheme and insurance companies' willingness to provide crop insurance to cocoa farmers. Multi-stage sampling technique was used to sample 240 farmers from four communities in the Dormaa West District in Brong-Ahafo Region. The double-hurdle model shows that age, marital status and education significantly and positively influenced cocoa farmer's willingness to insure their farms whiles household size and cropped area negatively influenced farmers' willingness to insure their farms. Similarly, age, household size and cropped area significantly and positively influenced the premium cocoa farmers were willing to pay whiles marital status and cocoa income negatively influenced the premium farmers were willing to pay. The contingent valuation method shows that the maximum, minimum and average amounts cocoa farmers are willing to pay for crop insurance per production cost per acre was GH¢128.40, GH¢32.10 and GH¢49.32 respectively. Insurance companies do not have crop insurance policy but willing to provide crop insurance policy to cocoa farmers on a condition that farmers adopt modern cultivation practices to reduce the level of risk. The study recommends that cocoa farmers should be well educated on crop insurance and should be involved in planning the crop insurance scheme in order to conclude on the premium to be paid by them.

  13. Entanglement and photon statistics of output fields from beam splitter for binomial state inputs

    Institute of Scientific and Technical Information of China (English)

    Zhou Qing-Ping; Fang Mao-Fa

    2004-01-01

    The entanglement properties are investigated based on linear entropy, and nonclassicalities are examined of output fields from a beam splitter for pure binomial state inputs. It is shown that the properties of the entanglement and the photon statistics of output fields are not only strongly dependent on the parameters of input binomial states but also quite involved with the nature of the beam splitter. The best entanglement can be obtained when the parameters of both input states and the beam splitter are chosen appropriately. Finally, we analyse briefly the distinguishability between the joint input state and the joint output state.

  14. Entanglement properties between two atoms in the binomial optical field interacting with two entangled atoms

    Institute of Scientific and Technical Information of China (English)

    刘堂昆; 张康隆; 陶宇; 单传家; 刘继兵

    2016-01-01

    The temporal evolution of the degree of entanglement between two atoms in a system of the binomial optical field interacting with two arbitrary entangled atoms is investigated. The influence of the strength of the dipole–dipole interaction between two atoms, probabilities of the Bernoulli trial, and particle number of the binomial optical field on the temporal evolution of the atomic entanglement are discussed. The result shows that the two atoms are always in the entanglement state. Moreover, if and only if the two atoms are initially in the maximally entangled state, the entanglement evolution is not affected by the parameters, and the degree of entanglement is always kept as 1.

  15. Empirical Bayes Point Estimates of True Score Using a Compound Binomial Error Model. Research Memorandum 74-11.

    Science.gov (United States)

    Kearns, Jack

    Empirical Bayes point estimates of true score may be obtained if the distribution of observed score for a fixed examinee is approximated in one of several ways by a well-known compound binomial model. The Bayes estimates of true score may be expressed in terms of the observed score distribution and the distribution of a hypothetical binomial test.…

  16. On the Residues of Binomial Coefficients and Their Products Modulo Prime Powers

    Institute of Scientific and Technical Information of China (English)

    CAI Tian Xin; GRANVILLE Andrew

    2002-01-01

    In this paper, we show several arithmetic properties on the residues of binomial coefficients and their products modulo prime powers, e.g.,((pq-1 (pq-1)/2)≡ (p-1 (p-1)/2)(q-1 (q-1)/2)(modpq),for any distinct odd primes p and q. Meanwhile, we discuss the connections with the prime recognitions.

  17. Evaluation of the generalized Goodwin Staton integral using binomial expansion theorem

    Science.gov (United States)

    Mamedov, B. A.

    2007-05-01

    A new analytical technique for evaluating the generalized Goodwin Staton integral (GGS) is described. A closed-form evaluation is presented. The GGS integral are expressed in terms of linear combinations of binomial coefficients and incomplete gamma function. A further comparison of analytical results with numerical models demonstrates a high accuracy of the developed analytical solution. The convergence of the results is shown.

  18. Enumerative and binomial sampling plans for citrus mealybug (Homoptera: pseudococcidae) in citrus groves.

    Science.gov (United States)

    Martínez-Ferrer, María Teresa; Ripollés, José Luís; Garcia-Marí, Ferran

    2006-06-01

    The spatial distribution of the citrus mealybug, Planococcus citri (Risso) (Homoptera: Pseudococcidae), was studied in citrus groves in northeastern Spain. Constant precision sampling plans were designed for all developmental stages of citrus mealybug under the fruit calyx, for late stages on fruit, and for females on trunks and main branches; more than 66, 286, and 101 data sets, respectively, were collected from nine commercial fields during 1992-1998. Dispersion parameters were determined using Taylor's power law, giving aggregated spatial patterns for citrus mealybug populations in three locations of the tree sampled. A significant relationship between the number of insects per organ and the percentage of occupied organs was established using either Wilson and Room's binomial model or Kono and Sugino's empirical formula. Constant precision (E = 0.25) sampling plans (i.e., enumerative plans) for estimating mean densities were developed using Green's equation and the two binomial models. For making management decisions, enumerative counts may be less labor-intensive than binomial sampling. Therefore, we recommend enumerative sampling plans for the use in an integrated pest management program in citrus. Required sample sizes for the range of population densities near current management thresholds, in the three plant locations calyx, fruit, and trunk were 50, 110-330, and 30, respectively. Binomial sampling, especially the empirical model, required a higher sample size to achieve equivalent levels of precision.

  19. Joint Analysis of Binomial and Continuous Traits with a Recursive Model

    DEFF Research Database (Denmark)

    Varona, Louis; Sorensen, Daniel

    2014-01-01

    This work presents a model for the joint analysis of a binomial and a Gaussian trait using a recursive parametrization that leads to a computationally efficient implementation. The model is illustrated in an analysis of mortality and litter size in two breeds of Danish pigs, Landrace and Yorkshir...

  20. Finite Time Ruin Probabilities and Large Deviations for Generalized Compound Binomial Risk Models

    Institute of Scientific and Technical Information of China (English)

    Yi Jun HU

    2005-01-01

    In this paper, we extend the classical compound binomial risk model to the case where the premium income process is based on a Poisson process, and is no longer a linear function. For this more realistic risk model, Lundberg type limiting results for the finite time ruin probabilities are derived. Asymptotic behavior of the tail probabilities of the claim surplus process is also investigated.

  1. Approximate order-up-to policies for inventory systems with binomial yield

    NARCIS (Netherlands)

    Ju, Wanrong; Gabor, Adriana F.; Ommeren, van Jan-Kees C.W.

    2013-01-01

    This paper studies an inventory policy for a retailer who orders his products from a supplier whose deliveries only partially satisfy the quality requirements. We model this situation by an infinite-horizon periodic-review model with binomial random yield and positive lead time. We propose an order-

  2. Approximate Order-up-to Policies for Inventory Systems with Binomial Yield

    NARCIS (Netherlands)

    W. Ju (Wanrong); A.F. Gabor (Adriana); J.C.W. van Ommeren (Jan-Kees)

    2013-01-01

    textabstractThis paper studies an inventory policy for a retailer who orders his products from a supplier whose deliveries only partially satisfy the quality require- ments. We model this situation by an infinite-horizon periodic-review model with binomial random yield and positive lead time. We pro

  3. Approximating Order-up-to Policies for Inventory Systems with Binomial Yield

    NARCIS (Netherlands)

    W. Ju (Wanrong); A.F. Gabor (Adriana); J.C.W. van Ommeren (Jan-Kees)

    2014-01-01

    markdownabstract__Abstract__ This paper studies an inventory policy for a retailer who orders his products from a supplier whose deliveries only partially satisfy the quality requirements. We model this situation by an innite-horizon periodic-review model with binomial random yield and positive lea

  4. The beta-binomial convolution model for 2 × 2 tables with missing cell counts

    NARCIS (Netherlands)

    Eisinga, Rob

    2009-01-01

    This paper considers the beta-binomial convolution model for the analysis of 2×2 tables with missing cell counts.We discuss maximumlikelihood (ML) parameter estimation using the expectation–maximization algorithm and study information loss relative to complete data estimators. We also examine bias o

  5. Raw and Central Moments of Binomial Random Variables via Stirling Numbers

    Science.gov (United States)

    Griffiths, Martin

    2013-01-01

    We consider here the problem of calculating the moments of binomial random variables. It is shown how formulae for both the raw and the central moments of such random variables may be obtained in a recursive manner utilizing Stirling numbers of the first kind. Suggestions are also provided as to how students might be encouraged to explore this…

  6. Approximate Order-up-to Policies for Inventory Systems with Binomial Yield

    NARCIS (Netherlands)

    W. Ju (Wanrong); A.F. Gabor (Adriana); J.C.W. van Ommeren (Jan-Kees)

    2013-01-01

    textabstractThis paper studies an inventory policy for a retailer who orders his products from a supplier whose deliveries only partially satisfy the quality require- ments. We model this situation by an infinite-horizon periodic-review model with binomial random yield and positive lead time. We

  7. Approximating Order-up-to Policies for Inventory Systems with Binomial Yield

    NARCIS (Netherlands)

    W. Ju (Wanrong); A.F. Gabor (Adriana); J.C.W. van Ommeren (Jan-Kees)

    2014-01-01

    markdownabstract__Abstract__ This paper studies an inventory policy for a retailer who orders his products from a supplier whose deliveries only partially satisfy the quality requirements. We model this situation by an innite-horizon periodic-review model with binomial random yield and

  8. Approximate order-up-to policies for inventory systems with binomial yield

    NARCIS (Netherlands)

    Ju, Wanrong; Gabor, Adriana F.; van Ommeren, Jan C.W.

    2013-01-01

    This paper studies an inventory policy for a retailer who orders his products from a supplier whose deliveries only partially satisfy the quality requirements. We model this situation by an infinite-horizon periodic-review model with binomial random yield and positive lead time. We propose an

  9. Pricing of perpetual American and Bermudan options by binomial tree method

    Institute of Scientific and Technical Information of China (English)

    LIN Jianwei; LIANG Jin

    2007-01-01

    In this paper, we consider the binomial tree method for pricing perpetual American and perpetual Bermudan options. The closed form solutions of these discrete models are solved. Explicit formulas for the optimal exercise boundary of the perpetual American option is obtained.A nonlinear equation that is satisfied by the optimal exercise boundaries of the perpetual Bermudan option is found.

  10. Multiplicity dependent and non-binomial efficiency corrections for particle number cumulants

    CERN Document Server

    Bzdak, Adam; Koch, Volker

    2016-01-01

    In this note we extend previous work on efficiency corrections for cumulant measurements [1,2]. We will discuss the limitations of the methods presented in these papers. Specifically we will consider multiplicity dependent efficiencies as well as a non-binomial efficiency distributions. We will discuss the most simple and straightforward methods to implement those corrections.

  11. A mixed-binomial model for Likert-type personality measures.

    Science.gov (United States)

    Allik, Jüri

    2014-01-01

    Personality measurement is based on the idea that values on an unobservable latent variable determine the distribution of answers on a manifest response scale. Typically, it is assumed in the Item Response Theory (IRT) that latent variables are related to the observed responses through continuous normal or logistic functions, determining the probability with which one of the ordered response alternatives on a Likert-scale item is chosen. Based on an analysis of 1731 self- and other-rated responses on the 240 NEO PI-3 questionnaire items, it was proposed that a viable alternative is a finite number of latent events which are related to manifest responses through a binomial function which has only one parameter-the probability with which a given statement is approved. For the majority of items, the best fit was obtained with a mixed-binomial distribution, which assumes two different subpopulations who endorse items with two different probabilities. It was shown that the fit of the binomial IRT model can be improved by assuming that about 10% of random noise is contained in the answers and by taking into account response biases toward one of the response categories. It was concluded that the binomial response model for the measurement of personality traits may be a workable alternative to the more habitual normal and logistic IRT models.

  12. Quantum Statistical Properties of Binomial Field Interacting with Two Entangled Atoms

    Institute of Scientific and Technical Information of China (English)

    JIAO Zhi-Yong; MA Jun-Mao; SHANG Yong-Tao; LI Ning; FU Xia

    2008-01-01

    Quantum statistical properties of the binomial field interacting with the two entangled atoms are investi-gated for the different initial conditions. It is found that the sub-Poissonian distribution and the antibunching effect can be presented for the certain ranges of the involved parameters.

  13. A Two-Stage Exercise on the Binomial Distribution Using Minitab.

    Science.gov (United States)

    Shibli, M. Abdullah

    1990-01-01

    Describes a two-stage experiment that was designed to explain binomial distribution to undergraduate statistics students. A manual coin flipping exercise is explained as the first stage; a computerized simulation using MINITAB software is presented as stage two; and output from the MINITAB exercises is included. (two references) (LRW)

  14. Computational results on the compound binomial risk model with nonhomogeneous claim occurrences

    NARCIS (Netherlands)

    Tuncel, A.; Tank, F.

    2013-01-01

    The aim of this paper is to give a recursive formula for non-ruin (survival) probability when the claim occurrences are nonhomogeneous in the compound binomial risk model. We give recursive formulas for non-ruin (survival) probability and for distribution of the total number of claims under the cond

  15. Hurdles in tissue engineering/regenerative medicine product commercialization: a survey of North American academia and industry.

    Science.gov (United States)

    Johnson, Peter C; Bertram, Timothy A; Tawil, Bill; Hellman, Kiki B

    2011-01-01

    The Tissue Engineering and Regenerative Medicine International Society-North America (TERMIS-NA) Industry Committee was formed in February 2009 to address the common roadblocks (i.e., hurdles) in the commercialization of tissue engineering/regenerative medicine products for its members. A semiquantitative online opinion survey instrument that delineated potentially sensitive hurdles to commercialization in each of the TERMIS constituency groups that generally participate in the stream of technology commercialization (academia, startup companies, development-stage companies, and established companies) was developed. The survey was opened to each of the 863 members of TERMIS-NA for a period of 5 weeks from October to November 2009. By its conclusion, 215 members (25%) had responded. Their proportionate numbers were closely representative of TERMIS-NA constituencies. The resulting data delineate what each group considers to be its most difficult and also its easiest hurdles in taking a technology to full product development. In addition, each group ranked its perception of the difficult and easy hurdles for all other groups, enabling an assessment of the degree of understanding between groups. The data depict not only critical hurdles in the path to commercialization at each stage in product development but also a variable understanding of perceptions of hurdles between groups. This assessment has provided the Industry Committee with activity foci needed to assist individual groups in the technology-commercialization stream. Moreover, the analysis suggests that enhanced communication between groups engaged in commercialization will be critical to the successful development of products in the tissue engineering/regenerative medicine sector.

  16. Ophthalmic Start-Up Chief Executive Officers' Perceptions of Development Hurdles.

    Science.gov (United States)

    Stewart, William C; Nelson, Lindsay A; Kruft, Bonnie; Stewart, Jeanette A

    2017-08-26

    To identify current challenges facing ophthalmic pharmaceutical start-ups in developing new products. Surveys were distributed to the chief executive officer (CEO) or president of ophthalmic start-ups. The survey attracted 24 responses from 78 surveys distributed (31%). The CEOs stated that a lack of financial capital (n = 18, 75%), FDA regulations (n = 6, 25%), and failure to meet clinical endpoints (n = 6, 25%) were their greatest development hurdles. Risk aversion to medicines in early development (n = 18, 75%), mergers and acquisitions reducing corporate choice for licensing agreements (n = 7, 29%), the emergence of large pharmaceutical-based venture capital funding groups (n = 12, 50%), and the failure of many large pharmaceutical companies to develop their own medicines (n = 10, 42%) were noted as recent prominent trends affecting fundraising. The study suggests that development funding, regulatory burden, and meeting clinical endpoints are the greatest development challenges faced by ophthalmic start-up CEOs. © 2017 S. Karger AG, Basel.

  17. About ATMPs, SOPs and GMP: The Hurdles to Produce Novel Skin Grafts for Clinical Use.

    Science.gov (United States)

    Hartmann-Fritsch, Fabienne; Marino, Daniela; Reichmann, Ernst

    2016-09-01

    The treatment of severe full-thickness skin defects represents a significant and common clinical problem worldwide. A bio-engineered autologous skin substitute would significantly reduce the problems observed with today's gold standard. Within 15 years of research, the Tissue Biology Research Unit of the University Children's Hospital Zurich has developed autologous tissue-engineered skin grafts based on collagen type I hydrogels. Those products are considered as advanced therapy medicinal products (ATMPs) and are routinely produced for clinical trials in a clean room facility following the guidelines for good manufacturing practice (GMP). This article focuses on hurdles observed for the translation of ATMPs from research into the GMP environment and clinical application. Personalized medicine in the field of rare diseases has great potential. However, ATMPs are mainly developed and promoted by academia, hospitals, and small companies, which face many obstacles such as high financial burdens.

  18. A novel series of conferences tackling the hurdles confronting the translation of novel cancer immunotherapies

    Directory of Open Access Journals (Sweden)

    Bot Adrian

    2012-11-01

    Full Text Available Abstract While there has been significant progress in advancing novel immune therapies to the bedside, much more needs to be done to fully tap into the potential of the immune system. It has become increasingly clear that besides practical and operational challenges, the heterogeneity of cancer and the limited efficacy profile of current immunotherapy platforms are the two main hurdles. Nevertheless, the promising clinical data of several approaches point to a roadmap that carries the promise to significantly advance cancer immunotherapy. A new annual series sponsored by Arrowhead Publishers and Conferences aims at bringing together scientific and business leadership from academia and industry, to identify, share and discuss most current priorities in research and translation of novel immune interventions. This Editorial provides highlights of the first event held earlier this year and outlines the focus of the second meeting to be held in 2013 that will be dedicated to stem cells and immunotherapy.

  19. Falls in Swedish hurdle and steeplechase racing and the condition of the track surface

    DEFF Research Database (Denmark)

    Gottlieb-Vedi, M.; Pipper, Christian Bressen

    2015-01-01

    Falls in National Hunt races is a tragic part of the sport. The present study focuses on the relation between racing track conditions and the number of falls in Swedish jump racing. The assumption was that more horses fell on heavy or soft going than on good or firm going. Results from all jump...... races at Täby Racecourse (1992-2001) were recorded. Parameters registered were: type and number of races, racing surface and condition, total time to finish the race, number of starting horses and number of falls. In this period 212 races, corresponding to 1,556 horse starts, were registered. Falls were...... registered in 42 races and in total 61 horses fell. The fall frequency on horse level was significantly higher in steeplechases than in hurdle races (odds ratio =3.69; 95% confidence interval (CI) = 1.99-6.85). For the steeplechases recorded in this study, significantly more falls were seen in long distance...

  20. Means and methods of teaching hurdling for children 11-12 years (Children and Youth Sports School

    Directory of Open Access Journals (Sweden)

    Nematov B.I.

    2010-08-01

    Full Text Available Expedience of application of general developing, special and basic exercises of hurdle-race is grounded. Facilities and methods of teaching and perfection a hurdle-race are certain. It is set that at teaching and perfection of technique it is expedient to differentiate the special and general developing exercises with integral competition motion. Selected exercise for development of mobility of joints and flexibility. The developed method allows to improve the level of development of power and speed capabilities. At the same time there is an increase of circumference of thorax, force of brush, vital capacity of lights.

  1. Application of a binomial cusum control chart to monitor one drinking water indicator

    Directory of Open Access Journals (Sweden)

    Elisa Henning

    2014-02-01

    Full Text Available The aim of this study is to analyze the use of a binomial cumulative sum chart (CUSUM to monitor the presence of total coliforms, biological indicators of quality of water supplies in water treatment processes. The sample series were monthly taken from a water treatment plant and were analyzed from 2007 to 2009. The statistical treatment of the data was performed using GNU R, and routines were created for the approximation of the upper limit of the binomial CUSUM chart. Furthermore, a comparative study was conducted to investigate whether there is a significant difference in sensitivity between the use of CUSUM and the traditional Shewhart chart, the most commonly used chart in process monitoring. The results obtained demonstrate that this study was essential for making the right choice in selecting a chart for the statistical analysis of this process.

  2. TESTING FOR VARYING DISPERSION OF LONGITUDINAL BINOMIAL DATA IN NONLINEAR LOGISTIC MODELS WITH RANDOM EFFECTS

    Institute of Scientific and Technical Information of China (English)

    林金官; 韦博成

    2004-01-01

    In this paper, it is discussed that two tests for varying dispersion of binomial data in the framework of nonlinear logistic models with random effects, which are widely used in analyzing longitudinal binomial data. One is the individual test and power calculation for varying dispersion through testing the randomness of cluster effects, which is extensions of Dean(1992) and Commenges et al (1994). The second test is the composite test for varying dispersion through simultaneously testing the randomness of cluster effects and the equality of random-effect means. The score test statistics are constructed and expressed in simple, easy to use, matrix formulas. The authors illustrate their test methods using the insecticide data (Giltinan, Capizzi & Malani (1988)).

  3. Quantum Correlation of Two Entangled Atoms Interacting with the Binomial Optical Field

    Science.gov (United States)

    Liu, Tang-Kun; Tao, Yu; Shan, Chuan-Jia; Liu, Ji-bing

    2016-10-01

    Quantum correlations of two atoms in a system of two entangled atoms interacting with the binomial optical field are investigated. In eight different initial states of the two atoms, the influence of the strength of the dipole-dipole interaction, probabilities of a the Bernoulli trial and particle number of the binomial optical field on the temporal evolution of the geometrical quantum discord between two atoms are discussed. The result shows that two atoms always exist the correlation for different parameters. In addition, when and only when the two atoms are initially in the maximally entangled state, the temporal evolution of geometrical quantum discord is not affected by the parameters, and always keep in the degree of geometrical quantum discord that is a fixed value.

  4. Comparison of multinomial and binomial proportion methods for analysis of multinomial count data.

    Science.gov (United States)

    Galyean, M L; Wester, D B

    2010-10-01

    Simulation methods were used to generate 1,000 experiments, each with 3 treatments and 10 experimental units/treatment, in completely randomized (CRD) and randomized complete block designs. Data were counts in 3 ordered or 4 nominal categories from multinomial distributions. For the 3-category analyses, category probabilities were 0.6, 0.3, and 0.1, respectively, for 2 of the treatments, and 0.5, 0.35, and 0.15 for the third treatment. In the 4-category analysis (CRD only), probabilities were 0.3, 0.3, 0.2, and 0.2 for treatments 1 and 2 vs. 0.4, 0.4, 0.1, and 0.1 for treatment 3. The 3-category data were analyzed with generalized linear mixed models as an ordered multinomial distribution with a cumulative logit link or by regrouping the data (e.g., counts in 1 category/sum of counts in all categories), followed by analysis of single categories as binomial proportions. Similarly, the 4-category data were analyzed as a nominal multinomial distribution with a glogit link or by grouping data as binomial proportions. For the 3-category CRD analyses, empirically determined type I error rates based on pair-wise comparisons (F- and Wald chi(2) tests) did not differ between multinomial and individual binomial category analyses with 10 (P = 0.38 to 0.60) or 50 (P = 0.19 to 0.67) sampling units/experimental unit. When analyzed as binomial proportions, power estimates varied among categories, with analysis of the category with the greatest counts yielding power similar to the multinomial analysis. Agreement between methods (percentage of experiments with the same results for the overall test for treatment effects) varied considerably among categories analyzed and sampling unit scenarios for the 3-category CRD analyses. Power (F-test) was 24.3, 49.1, 66.9, 83.5, 86.8, and 99.7% for 10, 20, 30, 40, 50, and 100 sampling units/experimental unit for the 3-category multinomial CRD analyses. Results with randomized complete block design simulations were similar to those with the CRD

  5. Use of the binomial distribution to predict impairment: application in a nonclinical sample.

    Science.gov (United States)

    Axelrod, Bradley N; Wall, Jacqueline R; Estes, Bradley W

    2008-01-01

    A mathematical model based on the binomial theory was developed to illustrate when abnormal score variations occur by chance in a multitest battery (Ingraham & Aiken, 1996). It has been successfully used as a comparison for obtained test scores in clinical samples, but not in nonclinical samples. In the current study, this model has been applied to demographically corrected scores on the Halstead-Reitan Neuropsychological Test Battery, obtained from a sample of 94 nonclinical college students. Results found that 15% of the sample had impairments suggested by the Halstead Impairment Index, using criteria established by Reitan and Wolfson (1993). In addition, one-half of the sample obtained impaired scores on one or two tests. These results were compared to that predicted by the binomial model and found to be consistent. The model therefore serves as a useful resource for clinicians considering the probability of impaired test performance.

  6. New method to estimate the sample size for calculation of a proportion assuming binomial distribution.

    Science.gov (United States)

    Vallejo, Adriana; Muniesa, Ana; Ferreira, Chelo; de Blas, Ignacio

    2013-10-01

    Nowadays the formula to calculate the sample size for estimate a proportion (as prevalence) is based on the Normal distribution, however it would be based on a Binomial distribution which confidence interval was possible to be calculated using the Wilson Score method. By comparing the two formulae (Normal and Binomial distributions), the variation of the amplitude of the confidence intervals is relevant in the tails and the center of the curves. In order to calculate the needed sample size we have simulated an iterative sampling procedure, which shows an underestimation of the sample size for values of prevalence closed to 0 or 1, and also an overestimation for values closed to 0.5. Attending to these results we proposed an algorithm based on Wilson Score method that provides similar values for the sample size than empirically obtained by simulation.

  7. Multiple analogues of binomial coefficients and related families of special numbers

    OpenAIRE

    Coskun, Hasan

    2010-01-01

    We construct multiple $qt$-binomial coefficients and related multiple analogues of several celebrated families of special numbers in this paper. These multidimensional generalizations include the first and the second kind of $qt$-Stirling numbers, $qt$-Bell numbers, $qt$-Bernoulli numbers, $qt$-Catalan numbers and the $qt$--Fibonacci numbers. In the course of developing main properties of these extensions, we prove results that are significant in their own rights such as certain probability m...

  8. Generalized harmonic, cyclotomic, and binomial sums, their polylogarithms and special numbers

    Energy Technology Data Exchange (ETDEWEB)

    Ablinger, J.; Schneider, C. [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC); Bluemlein, J. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2013-10-15

    A survey is given on mathematical structures which emerge in multi-loop Feynman diagrams. These are multiply nested sums, and, associated to them by an inverse Mellin transform, specific iterated integrals. Both classes lead to sets of special numbers. Starting with harmonic sums and polylogarithms we discuss recent extensions of these quantities as cyclotomic, generalized (cyclotomic), and binomially weighted sums, associated iterated integrals and special constants and their relations.

  9. Bethe states for the two-site Bose–Hubbard model: A binomial approach

    Directory of Open Access Journals (Sweden)

    Gilberto Santos

    2015-06-01

    Full Text Available We calculate explicitly the Bethe vectors states by the algebraic Bethe ansatz method with the gl(2-invariant R-matrix for the two-site Bose–Hubbard model. Using a binomial expansion of the n-th power of a sum of two operators we get and solve a recursion equation. We calculate the scalar product and the norm of the Bethe vectors states. The form factors of the imbalance current operator are also computed.

  10. The role of Poisson's binomial distribution in the analysis of TEM images.

    Science.gov (United States)

    Tejada, Arturo; den Dekker, Arnold J

    2011-11-01

    Frank's observation that a TEM bright-field image acquired under non-stationary conditions can be modeled by the time integral of the standard TEM image model [J. Frank, Nachweis von objektbewegungen im lichtoptis- chen diffraktogramm von elektronenmikroskopischen auf- nahmen, Optik 30 (2) (1969) 171-180.] is re-derived here using counting statistics based on Poisson's binomial distribution. The approach yields a statistical image model that is suitable for image analysis and simulation.

  11. Wigner functions and tomograms of the even and odd binomial states

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiao-Yan; Wang Ji-Suo; Meng Xiang-Guo; Su Jie

    2009-01-01

    Using the coherent state representation of Wigner operator and the technique of integration within an ordered product (IWOP) of operators, the Wigner functions of the even and odd binomial states (EOBSs) are obtained. The physical meaning of the Wigner functions for the EOBSs is given by means of their marginal distributions. Moreover, the tomograms of the EOBSs are calculated by virtue of intermediate coordinate-momentum representation in quantum optics.

  12. Binomial and enumerative sampling of Tetranychus urticae (Acari: Tetranychidae) on peppermint in California.

    Science.gov (United States)

    Tollerup, Kris E; Marcum, Daniel; Wilson, Rob; Godfrey, Larry

    2013-08-01

    The two-spotted spider mite, Tetranychus urticae Koch, is an economic pest on peppermint [Mentha x piperita (L.), 'Black Mitcham'] grown in California. A sampling plan for T. urticae was developed under Pacific Northwest conditions in the early 1980s and has been used by California growers since approximately 1998. This sampling plan, however, is cumbersome and a poor predictor of T. urticae densities in California. Between June and August, the numbers of immature and adult T. urticae were counted on leaves at three commercial peppermint fields (sites) in 2010 and a single field in 2011. In each of seven locations per site, 45 leaves were sampled, that is, 9 leaves per five stems. Leaf samples were stratified by collecting three leaves from the top, middle, and bottom strata per stem. The on-plant distribution of T. urticae did not significantly differ among the stem strata through the growing season. Binomial and enumerative sampling plans were developed using generic Taylor's power law coefficient values. The best fit of our data for binomial sampling occurred using a tally threshold of T = 0. The optimum number of leaves required for T urticae at the critical density of five mites per leaf was 20 for the binomial and 23 for the enumerative sampling plans, respectively. Sampling models were validated using Resampling for Validation of Sampling Plan Software.

  13. Meta-analysis for diagnostic accuracy studies: a new statistical model using beta-binomial distributions and bivariate copulas.

    Science.gov (United States)

    Kuss, Oliver; Hoyer, Annika; Solms, Alexander

    2014-01-15

    There are still challenges when meta-analyzing data from studies on diagnostic accuracy. This is mainly due to the bivariate nature of the response where information on sensitivity and specificity must be summarized while accounting for their correlation within a single trial. In this paper, we propose a new statistical model for the meta-analysis for diagnostic accuracy studies. This model uses beta-binomial distributions for the marginal numbers of true positives and true negatives and links these margins by a bivariate copula distribution. The new model comes with all the features of the current standard model, a bivariate logistic regression model with random effects, but has the additional advantages of a closed likelihood function and a larger flexibility for the correlation structure of sensitivity and specificity. In a simulation study, which compares three copula models and two implementations of the standard model, the Plackett and the Gauss copula do rarely perform worse but frequently better than the standard model. We use an example from a meta-analysis to judge the diagnostic accuracy of telomerase (a urinary tumor marker) for the diagnosis of primary bladder cancer for illustration.

  14. 高栏跨栏跑速度特点及其训练%Speed Characteristics and Training of the 110-meter Hurdle Race

    Institute of Scientific and Technical Information of China (English)

    刘旭东; 梅峰

    2011-01-01

    通过高栏跨栏跑速度特点及其训练方法,认为要提高跨栏专项成绩,就必须解决好栏上的过栏速度和栏间的平跑速度.过栏速度是靠提高起跨腿蹬地速度、摆动腿动作速度、起跨腿提拉速度和下栏转为栏间跑速度;栏间平跑速度是以提高栏间步频为主.揭示了跨栏跑平跑速度、过栏速度的重要性,对两者提出了科学的训练方案.%To enhance the special grade of hurdle, athletes must speed up while getting over the hurdle and running between two hurdles. The speed getting over the hurdle mainly depends on the speed of trail leg when thrusting against the ground, swinging legs, pull through of trailing leg and the speed of turning into running between hurdles from driving down off the hurdle. The speed of stride between hurdles depends on improving stride frequency for the most part. It can be seen that speed of middle running and getting over the hurdle are very important. Based on it, this paper puts forward a scientific training plan for both of them.

  15. Hurdle technology applied to prickly pear beverages for inhibiting Saccharomyces cerevisiae and Escherichia coli.

    Science.gov (United States)

    García-García, R; Escobedo-Avellaneda, Z; Tejada-Ortigoza, V; Martín-Belloso, O; Valdez-Fragoso, A; Welti-Chanes, J

    2015-06-01

    The effect of pH reduction (from 6·30-6·45 to 4·22-4·46) and the addition of antimicrobial compounds (sodium benzoate and potassium sorbate) on the inhibition of Saccharomyces cerevisiae and Escherichia coli in prickly pear beverages formulated with the pulp and peel of Villanueva (V, Opuntia albicarpa) and Rojo Vigor (RV, Opuntia ficus-indica) varieties during 14 days of storage at 25°C, was evaluated. RV variety presented the highest microbial inhibition. By combining pH reduction and preservatives, reductions of 6·2-log10 and 2·3-log10 for E. coli and S. cerevisiae were achieved respectively. Due to the low reduction of S. cerevisiae, pulsed electric fields (PEF) (11-15 μs/25-50 Hz/27-36 kV cm(-1)) was applied as another preservation factor. The combination of preservatives, pH reduction and PEF at 13-15 μs/25-50 Hz for V variety, and 11 μs/50 Hz, 13-15 μs/25-50 Hz for RV, had a synergistic effect on S. cerevisiae inhibition, achieving at least 3·4-log10 of microbial reduction immediately after processing, and more than 5-log10 at fourth day of storage at 25°C maintained this reduction during 21 days of storage (P > 0·05). Hurdle technology using PEF in combination with other factors is adequate to maintain stable prickly pear beverages during 21 days/25°C. Significance and impact of the study: Prickly pear is a fruit with functional value, with high content of nutraceuticals and antioxidant activity. Functional beverages formulated with the pulp and peel of this fruit represent an alternative for its consumption. Escherichia coli and Saccharomyces cerevisiae are micro-organisms that typically affect fruit beverage quality and safety. The food industry is looking for processing technologies that maintain quality without compromising safety. Hurdle technology, including pulsed electric fields (PEF) could be an option to achieve this. The combination of PEF, pH reduction and preservatives is an alternative to obtain safe and minimally processed

  16. A Simple Explanation of Negative Correlation Data in p^^-p Annihilations

    OpenAIRE

    Hujio, NODA; Department of Physics, Ibaraki University

    1983-01-01

    Negative correlation data in p^^-p annihilations at low energies are explained by a simple model, in which the normalized cross section for the negative-charged multiplicity is represented by binomial distribution. It satisfies the multiplicity cutoff required by the energy conservation and shows an approximate KNO scaling.

  17. Regulatory hurdles for genome editing: process- vs. product-based approaches in different regulatory contexts.

    Science.gov (United States)

    Sprink, Thorben; Eriksson, Dennis; Schiemann, Joachim; Hartung, Frank

    2016-07-01

    Novel plant genome editing techniques call for an updated legislation regulating the use of plants produced by genetic engineering or genome editing, especially in the European Union. Established more than 25 years ago and based on a clear distinction between transgenic and conventionally bred plants, the current EU Directives fail to accommodate the new continuum between genetic engineering and conventional breeding. Despite the fact that the Directive 2001/18/EC contains both process- and product-related terms, it is commonly interpreted as a strictly process-based legislation. In view of several new emerging techniques which are closer to the conventional breeding than common genetic engineering, we argue that it should be actually interpreted more in relation to the resulting product. A legal guidance on how to define plants produced by exploring novel genome editing techniques in relation to the decade-old legislation is urgently needed, as private companies and public researchers are waiting impatiently with products and projects in the pipeline. We here outline the process in the EU to develop a legislation that properly matches the scientific progress. As the process is facing several hurdles, we also compare with existing frameworks in other countries and discuss ideas for an alternative regulatory system.

  18. In-vitro regeneration studies of an important legume, Cicer arietinum: Hurdles and future prospects

    Directory of Open Access Journals (Sweden)

    Pragati Kumari

    2015-06-01

    Full Text Available There are several economically important grain legumes including chickpea that play significant role in nutrition of the rural and urban poor in developing world. Plants are subjected to a large number of stresses that may interfere with the normal growth and development. The model legumes are being developed as experimental systems to study a number of key biological questions using molecular tools including genomics and proteomics. Most of the functional genomics approaches rely upon the highthroughput transformation system useful for studying various gene identification strategies. The difficulty to transform a plant varies from species to species in legumes. There is limited success in exchange of the desirable characters by the classical and modern breeding technologies, in important pulse crop chickpea and biotechnological tools like plant tissue culture and genetic transformation techniques have emerged as a potential supplement. The major bottleneck is requirement of an in vitro manipulation of leguminosae members and the availability of reproducible, efficient and better plant regeneration methods. The regeneration and transformation of legumes particularly chickpea suffers due to recalcitrant nature towards rooting and transplantation of the in vitro regenerated plants. This becomes a limiting factor for the application of this technology towards designated mandate of crop improvement programs. This article discusses the hurdles and strategies for transformation of legumes in general and chickpea in particular.

  19. Semantic Web for Chemical Genomics – need, how to, and hurdles

    Directory of Open Access Journals (Sweden)

    Talapady Bhat

    2007-08-01

    Full Text Available Semantic Web has been often suggested as the information technology solution to the growing problem in managing the millions of data points generated by modern science such as nanotechnology and high through-put screening for drugs. However, the progress towards this vision envisaged by the W3C has been very limited. Here we discuss –some of the obstacles to the realization of this vision and we make some suggestions as to how one may overcome some of these hurdles? Here we discuss some of these issues and present thoughts on an alternative method to Semantic Web that is less drastic in requirements. This method does not require the use of RDF and Protege, and it works in an environment currently used by the chemical and biological database providers. In our method one attempts to use as many components as possible from the tools already used by the database providers and one brings in far fewer new tools and techniques compared to the method that use RDF or Protégé. Our method uses a standard database environment and web tools rather than the RDF and Protégé to manage user interface and the data is held in a database rather than using RDF. This method shifts the task of building Semantic knowledge-base and ontology from RDF and Protégé to a SQL based database environment.

  20. Red blood cells from induced pluripotent stem cells: hurdles and developments.

    Science.gov (United States)

    Mazurier, Christelle; Douay, Luc; Lapillonne, Hélène

    2011-07-01

    In the context of chronic blood supply difficulties, generating cultured red blood cells (cRBCs) in vitro after amplification of stem cells makes sense. This review will focus on the recent findings about the generation of erythroid cells from induced pluripotent stem (iPS) cells and deals with the hurdles and next developments that will occur. The most proliferative source of stem cells for generating cRBCs is the cord blood, but this source is limited in terms of hematopoietic stem cells and dependent on donations. Pluripotent stem cells are thus the best candidates and potential sources of cRBCs. Critical advances have led towards the in-vitro production of functional RBCs from iPS cells in the last few years. Because iPS cells can proliferate indefinitely and can be selected for a phenotype of interest, they are potential candidates to organize complementary sources of RBCs for transfusion. Proof of concept of generating cRBCs from iPS cells has been performed, but the procedures need to be optimized to lead to clinical application in blood transfusion. Several crucial points remain to be resolved. Notably these include the choice of the initial cell type to generate iPS cells, the method of reprogramming, that is, to ensure the safety of iPS cells as clinical grade, the optimization of erythrocyte differentiation, and the definition of good manufacturing practice (GMP) conditions for industrial production.

  1. Partitioning detectability components in populations subject to within-season temporary emigration using binomial mixture models.

    Directory of Open Access Journals (Sweden)

    Katherine M O'Donnell

    Full Text Available Detectability of individual animals is highly variable and nearly always < 1; imperfect detection must be accounted for to reliably estimate population sizes and trends. Hierarchical models can simultaneously estimate abundance and effective detection probability, but there are several different mechanisms that cause variation in detectability. Neglecting temporary emigration can lead to biased population estimates because availability and conditional detection probability are confounded. In this study, we extend previous hierarchical binomial mixture models to account for multiple sources of variation in detectability. The state process of the hierarchical model describes ecological mechanisms that generate spatial and temporal patterns in abundance, while the observation model accounts for the imperfect nature of counting individuals due to temporary emigration and false absences. We illustrate our model's potential advantages, including the allowance of temporary emigration between sampling periods, with a case study of southern red-backed salamanders Plethodon serratus. We fit our model and a standard binomial mixture model to counts of terrestrial salamanders surveyed at 40 sites during 3-5 surveys each spring and fall 2010-2012. Our models generated similar parameter estimates to standard binomial mixture models. Aspect was the best predictor of salamander abundance in our case study; abundance increased as aspect became more northeasterly. Increased time-since-rainfall strongly decreased salamander surface activity (i.e. availability for sampling, while higher amounts of woody cover objects and rocks increased conditional detection probability (i.e. probability of capture, given an animal is exposed to sampling. By explicitly accounting for both components of detectability, we increased congruence between our statistical modeling and our ecological understanding of the system. We stress the importance of choosing survey locations and

  2. Analysis of the short form-36 (SF-36): the beta-binomial distribution approach.

    Science.gov (United States)

    Arostegui, Inmaculada; Núñez-Antón, Vicente; Quintana, José M

    2007-03-15

    Health-related quality of life (HRQoL) is an important indicator of health status and the Short Form-36 (SF-36) is a generic instrument to measure it. Multiple linear regression (MLR) is often used to study the relationship of HRQoL with patients' characteristics, though HRQoL outcomes tend to be not normally distributed, skewed and bounded (e.g. between 0 and 100). A sample of 193 patients with eating disorders has been analysed to assess the performance of the MLR under non-normality conditions. Normal distribution was rejected for seven out of the eight domains. A beta-binomial distribution is suggested to fit the SF-36 scores. The beta-binomial distribution is not rejected for five out of the eight domains. Thus, a beta-binomial regression (BBR) is suggested to analyse the SF-36 scores. Results using MLR and BBR have been compared for real and simulated data. Performance of the BBR is shown to be better than MLR in the HRQoL domains with few ordered categories and very similar to MLR in the more continuous domains. Moreover, the interpretation of the estimates obtained with BBR is clinically more meaningful. A common technique of statistical analysis is preferable for all the HRQoL dimensions. Therefore, the BBR approach is recommended not only to detect significant predictors of HRQoL when SF-36 is used, but also to analyse and interpret the effect of several explanatory variables on HRQoL. Further work is required to test the better performance of BBR against standard methods for other HRQoL outcomes, populations or interventions.

  3. Beta-binomial model for meta-analysis of odds ratios.

    Science.gov (United States)

    Bakbergenuly, Ilyas; Kulinskaya, Elena

    2017-01-25

    In meta-analysis of odds ratios (ORs), heterogeneity between the studies is usually modelled via the additive random effects model (REM). An alternative, multiplicative REM for ORs uses overdispersion. The multiplicative factor in this overdispersion model (ODM) can be interpreted as an intra-class correlation (ICC) parameter. This model naturally arises when the probabilities of an event in one or both arms of a comparative study are themselves beta-distributed, resulting in beta-binomial distributions. We propose two new estimators of the ICC for meta-analysis in this setting. One is based on the inverted Breslow-Day test, and the other on the improved gamma approximation by Kulinskaya and Dollinger (2015, p. 26) to the distribution of Cochran's Q. The performance of these and several other estimators of ICC on bias and coverage is studied by simulation. Additionally, the Mantel-Haenszel approach to estimation of ORs is extended to the beta-binomial model, and we study performance of various ICC estimators when used in the Mantel-Haenszel or the inverse-variance method to combine ORs in meta-analysis. The results of the simulations show that the improved gamma-based estimator of ICC is superior for small sample sizes, and the Breslow-Day-based estimator is the best for n⩾100. The Mantel-Haenszel-based estimator of OR is very biased and is not recommended. The inverse-variance approach is also somewhat biased for ORs≠1, but this bias is not very large in practical settings. Developed methods and R programs, provided in the Web Appendix, make the beta-binomial model a feasible alternative to the standard REM for meta-analysis of ORs. © 2017 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

  4. Establishing equivalence for microbial-growth-inhibitory effects ("iso-hurdle rules") by analyzing disparate listeria monocytogenes data with a gamma-type predictive model.

    Science.gov (United States)

    Pujol, Laure; Kan-King-Yu, Denis; Le Marc, Yvan; Johnston, Moira D; Rama-Heuzard, Florence; Guillou, Sandrine; McClure, Peter; Membré, Jeanne-Marie

    2012-02-01

    Preservative factors act as hurdles against microorganisms by inhibiting their growth; these are essential control measures for particular food-borne pathogens. Different combinations of hurdles can be quantified and compared to each other in terms of their inhibitory effect ("iso-hurdle"). We present here a methodology for establishing microbial iso-hurdle rules in three steps: (i) developing a predictive model based on existing but disparate data sets, (ii) building an experimental design focused on the iso-hurdles using the model output, and (iii) validating the model and the iso-hurdle rules with new data. The methodology is illustrated with Listeria monocytogenes. Existing data from industry, a public database, and the literature were collected and analyzed, after which a total of 650 growth rates were retained. A gamma-type model was developed for the factors temperature, pH, a(w), and acetic, lactic, and sorbic acids. Three iso-hurdle rules were assessed (40 logcount curves generated): salt replacement by addition of organic acids, sorbic acid replacement by addition of acetic and lactic acid, and sorbic acid replacement by addition of lactic/acetic acid and salt. For the three rules, the growth rates were equivalent in the whole experimental domain (γ from 0.1 to 0.5). The lag times were also equivalent in the case of mild inhibitory conditions (γ ≥ 0.2), while they were longer in the presence of salt than acids under stress conditions (γ microbial safety and stability.

  5. The Kolmogorov Distance between the Binomial and Poisson Laws: Efficient Algorithms and Sharp Estimates

    Directory of Open Access Journals (Sweden)

    José A. Adell

    2009-01-01

    Full Text Available We give efficient algorithms, as well as sharp estimates, to compute the Kolmogorov distance between the binomial and Poisson laws with the same mean λ. Such a distance is eventually attained at the integer part of λ+1/2−λ+1/4. The exact Kolmogorov distance for λ≤2−2 is also provided. The preceding results are obtained as a concrete application of a general method involving a differential calculus for linear operators represented by stochastic processes.

  6. Preliminary Test Estimators and Phi-divergence Measures in Pooling Binomial Data

    Directory of Open Access Journals (Sweden)

    N. Martin

    2012-07-01

    Full Text Available Two independent random samples are drawn from two Binomial populations with parameters theta1 and  theta2 respectively. Ahmed (1991 considered a preliminary test estimator based on maximum likelihood estimator for estimating theta1 when it is suspected that theta1=theta2.  In this paper we combine minimum phi-divergence estimators as well as phi-divergence test statistics in order to define a preliminary phi-divergence test estimators. These new estimators are compared with the classical estimator as well as the pooled estimator.

  7. Developing a Symptom Validity Test for posttraumatic stress disorder: application of the binomial distribution.

    Science.gov (United States)

    Morel, Kenneth R; Shepherd, Bryan E

    2008-12-01

    The past decade has witnessed a significant increase in research on the detection of malingered Posttraumatic Stress Disorder (PTSD) in civil litigation, other disability pension contexts, and in forensic cases. This article reviews the basic principles and statistical procedures that can be used to design and develop a Symptom Validity Test (SVT) for PTSD. We demonstrate how the practical application of the binomial distribution can detect response bias in specific psychiatric disorders such as PTSD and can provide empirically grounded probabilistic evidence of malingering. We cite the Morel Emotional Numbing Test for Posttraumatic Stress Disorder (MENT) as an example.

  8. Bayesian sample size calculation for estimation of the difference between two binomial proportions.

    Science.gov (United States)

    Pezeshk, Hamid; Nematollahi, Nader; Maroufy, Vahed; Marriott, Paul; Gittins, John

    2013-12-01

    In this study, we discuss a decision theoretic or fully Bayesian approach to the sample size question in clinical trials with binary responses. Data are assumed to come from two binomial distributions. A Dirichlet distribution is assumed to describe prior knowledge of the two success probabilities p1 and p2. The parameter of interest is p = p1 - p2. The optimal size of the trial is obtained by maximising the expected net benefit function. The methodology presented in this article extends previous work by the assumption of dependent prior distributions for p1 and p2.

  9. proportion: A comprehensive R package for inference on single Binomial proportion and Bayesian computations

    Science.gov (United States)

    Subbiah, M.; Rajeswaran, V.

    Extensive statistical practice has shown the importance and relevance of the inferential problem of estimating probability parameters in a binomial experiment; especially on the issues of competing intervals from frequentist, Bayesian, and Bootstrap approaches. The package written in the free R environment and presented in this paper tries to take care of the issues just highlighted, by pooling a number of widely available and well-performing methods and apporting on them essential variations. A wide range of functions helps users with differing skills to estimate, evaluate, summarize, numerically and graphically, various measures adopting either the frequentist or the Bayesian paradigm.

  10. Evaluating components of dental care utilization among adults with diabetes and matched controls via hurdle models

    Directory of Open Access Journals (Sweden)

    Chaudhari Monica

    2012-07-01

    Full Text Available Abstract Background About one-third of adults with diabetes have severe oral complications. However, limited previous research has investigated dental care utilization associated with diabetes. This project had two purposes: to develop a methodology to estimate dental care utilization using claims data and to use this methodology to compare utilization of dental care between adults with and without diabetes. Methods Data included secondary enrollment and demographic data from Washington Dental Service (WDS and Group Health Cooperative (GH, clinical data from GH, and dental-utilization data from WDS claims during 2002–2006. Dental and medical records from WDS and GH were linked for enrolees continuously and dually insured during the study. We employed hurdle models in a quasi-experimental setting to assess differences between adults with and without diabetes in 5-year cumulative utilization of dental services. Propensity score matching adjusted for differences in baseline covariates between the two groups. Results We found that adults with diabetes had lower odds of visiting a dentist (OR = 0.74, p  0.001. Among those with a dental visit, diabetes patients had lower odds of receiving prophylaxes (OR = 0.77, fillings (OR = 0.80 and crowns (OR = 0.84 (p 0.005 for all and higher odds of receiving periodontal maintenance (OR = 1.24, non-surgical periodontal procedures (OR = 1.30, extractions (OR = 1.38 and removable prosthetics (OR = 1.36 (p  Conclusions Patients with diabetes are less likely to use dental services. Those who do are less likely to use preventive care and more likely to receive periodontal care and tooth-extractions. Future research should address the possible effectiveness of additional prevention in reducing subsequent severe oral disease in patients with diabetes.

  11. Four hurdles for conservation on private land: the case of the golden lion tamarin, Atlantic Forest, Brazil.

    Directory of Open Access Journals (Sweden)

    Ralf Christopher Buckley

    2015-08-01

    Full Text Available Many threatened species worldwide rely on patches of remnant vegetation in private landholdings. To establish private reserves that contribute effectively to conservation involves a wide range of complex and interacting ecological, legal, social and financial factors. These can be seen as a series of successive hurdles, each with multiple bars, which must all be surmounted. The golden lion tamarin, Leontopithecus rosalia, is restricted to the Atlantic Forest biome in the state of Rio de Janeiro, Brazil. This forest is largely cleared. There are many small remnant patches on private lands, able to support tamarins. Local NGO’s have successfully used limited funds to contribute to tamarin conservation in a highly cost effective way. We examined the mechanisms by analysing documents and interviewing landholders and other stakeholders. We found that the local NGOs successfully identified landholdings where ecological, legal, social and some financial hurdles had already been crossed, and helped landholders over the final financial hurdle by funding critical cost components. This cost <5% of the price of outright land purchase. This approach is scaleable for golden lion tamarin elsewhere within the Atlantic Forest biome, and applicable for other species and ecosystems worldwide.

  12. Mechanisms of adaptation to intensive loads of 400 meters’ hurdles runners at stage of initial basic training

    Directory of Open Access Journals (Sweden)

    Rovniy A.S.

    2015-08-01

    Full Text Available Purpose: is study of adaptation mechanisms of 400 meter’ hurdles-runners to intensive physical loads. Material: in the research 13 - 400 meters’ hurdles-runners and 13 - 400 meters’ runners participated. Results: it was found that physiological cost of sportsmen’s special workability has fragmentary character. We presented results of physiological and bio-chemical adaptation mechanisms to dozed work. The received results have no confident distinctions and can not objectively characterize mechanisms of sportsmen’s special workability. We did not detect definite differences in indicators of mechanisms, ensuring sportsmen’s special workability under dozed loads. We found, that level of anaerobic glycolysis is an objective criterion of 400 meter’ hurdles-runners’ special workability. It was shown that for determination of functional potentials for such kind of functioning it is necessary to apply special loads. Conclusions: the received results deepen information about mechanisms of adaptation to specific competition functioning. Correct approaches to processing and analysis of the research’s results permit to more specifically determine sportsmen’s functional potentials in different kinds of competition functioning.

  13. Identifying economic hurdles to early adoption of preventative practices: The case of trunk diseases in California winegrape vineyards

    Directory of Open Access Journals (Sweden)

    Jonathan Kaplan

    2016-12-01

    Full Text Available Despite the high likelihood of infection and substantial yield losses from trunk diseases, many California practitioners wait to adopt field-tested, preventative practices (delayed pruning, double pruning, and application of pruning-wound protectants until after disease symptoms appear in the vineyard at around 10 years old. We evaluate net benefits from adoption of these practices before symptoms appear in young Cabernet Sauvignon vineyards and after they become apparent in mature vineyards to identify economic hurdles to early adoption. We simulate winegrape production in select counties of California and find widespread benefits from early adoption, increasing vineyard profitable lifespans, in some cases, by close to 50%. However, hurdles may result from uncertainty about the cost and returns from adoption, labor constraints, long time lags in benefits from early adoption, growers’ perceived probabilities of infection, and their discount rate. Development of extension resources communicating benefits and potential hurdles to growers likely reduces uncertainty, increasing early adoption. Improvements in efficacy of preventative practices, perhaps by detecting when pathogen spores are released into the vineyard, will increase early adoption. Lastly, practice cost reductions will increase early adoption too, especially when the time it takes for adoption to payoff and infection uncertainty are influential in adoption decisions.

  14. Comparison and Field Validation of Binomial Sampling Plans for Oligonychus perseae (Acari: Tetranychidae) on Hass Avocado in Southern California.

    Science.gov (United States)

    Lara, Jesus R; Hoddle, Mark S

    2015-08-01

    Oligonychus perseae Tuttle, Baker, & Abatiello is a foliar pest of 'Hass' avocados [Persea americana Miller (Lauraceae)]. The recommended action threshold is 50-100 motile mites per leaf, but this count range and other ecological factors associated with O. perseae infestations limit the application of enumerative sampling plans in the field. Consequently, a comprehensive modeling approach was implemented to compare the practical application of various binomial sampling models for decision-making of O. perseae in California. An initial set of sequential binomial sampling models were developed using three mean-proportion modeling techniques (i.e., Taylor's power law, maximum likelihood, and an empirical model) in combination with two-leaf infestation tally thresholds of either one or two mites. Model performance was evaluated using a robust mite count database consisting of >20,000 Hass avocado leaves infested with varying densities of O. perseae and collected from multiple locations. Operating characteristic and average sample number results for sequential binomial models were used as the basis to develop and validate a standardized fixed-size binomial sampling model with guidelines on sample tree and leaf selection within blocks of avocado trees. This final validated model requires a leaf sampling cost of 30 leaves and takes into account the spatial dynamics of O. perseae to make reliable mite density classifications for a 50-mite action threshold. Recommendations for implementing this fixed-size binomial sampling plan to assess densities of O. perseae in commercial California avocado orchards are discussed.

  15. Modeling random telegraph signal noise in CMOS image sensor under low light based on binomial distribution

    Science.gov (United States)

    Yu, Zhang; Xinmiao, Lu; Guangyi, Wang; Yongcai, Hu; Jiangtao, Xu

    2016-07-01

    The random telegraph signal noise in the pixel source follower MOSFET is the principle component of the noise in the CMOS image sensor under low light. In this paper, the physical and statistical model of the random telegraph signal noise in the pixel source follower based on the binomial distribution is set up. The number of electrons captured or released by the oxide traps in the unit time is described as the random variables which obey the binomial distribution. As a result, the output states and the corresponding probabilities of the first and the second samples of the correlated double sampling circuit are acquired. The standard deviation of the output states after the correlated double sampling circuit can be obtained accordingly. In the simulation section, one hundred thousand samples of the source follower MOSFET have been simulated, and the simulation results show that the proposed model has the similar statistical characteristics with the existing models under the effect of the channel length and the density of the oxide trap. Moreover, the noise histogram of the proposed model has been evaluated at different environmental temperatures. Project supported by the National Natural Science Foundation of China (Grant Nos. 61372156 and 61405053) and the Natural Science Foundation of Zhejiang Province of China (Grant No. LZ13F04001).

  16. Modeling random telegraph signal noise in CMOS image sensor under low light based on binomial distribution

    Institute of Scientific and Technical Information of China (English)

    张钰; 逯鑫淼; 王光义; 胡永才; 徐江涛

    2016-01-01

    The random telegraph signal noise in the pixel source follower MOSFET is the principle component of the noise in the CMOS image sensor under low light. In this paper, the physical and statistical model of the random telegraph signal noise in the pixel source follower based on the binomial distribution is set up. The number of electrons captured or released by the oxide traps in the unit time is described as the random variables which obey the binomial distribution. As a result, the output states and the corresponding probabilities of the first and the second samples of the correlated double sampling circuit are acquired. The standard deviation of the output states after the correlated double sampling circuit can be obtained accordingly. In the simulation section, one hundred thousand samples of the source follower MOSFET have been simulated, and the simulation results show that the proposed model has the similar statistical characteristics with the existing models under the effect of the channel length and the density of the oxide trap. Moreover, the noise histogram of the proposed model has been evaluated at different environmental temperatures.

  17. CUANDO FALLA EL SUPUESTO DE HOMOCEDASTICIDAD EN VARIABLES CON DISTRIBUCIÓN BINOMIAL

    Directory of Open Access Journals (Sweden)

    Edison Ramiro Vásquez

    2011-01-01

    Full Text Available Se utilizó el proceso de Simulación de Monte Carlopara generar poblaciones de variables aleatorias con distribuciónBinomial con varianzas homogéneas y heterogéneas; para cinco,10 y 30 observaciones por unidad experimental (n y probabi-lidad de éxito del evento de 0,10, 0,20, ¿,0,90(p. Se conformaronexperimentos en Diseño Bloques al Azar con tres, cinco y nuevetratamientos (t; cuatro y ocho réplicas(r; para cada combinaciónt-r-n, se generaron 100 experimentos. A modo de disponer deun referente de discusión, se incluyó la variante de otros 100experimentos de variables con distribución Normal, con similaresmedias y varianzas de los experimentos de datos con distribuciónBinomial. Se comprobó que el comportamiento de losindicadores: porcentaje de experimentos en que se produce unrechazo de la hipótesis H0; la potencia en el ANOVA; diferenciamínima detectada en el experimento, así como el número dediferencias entre medias de tratamientos, es similar dentro decada alternativa de análisis a través de las tres variantes;evidenciando una marcada influencia el número de observaciones por unidad experimental y el número de réplicas en estosindicadores.

  18. Modeling and Predistortion of Envelope Tracking Power Amplifiers using a Memory Binomial Model

    DEFF Research Database (Denmark)

    Tafuri, Felice Francesco; Sira, Daniel; Larsen, Torben

    2013-01-01

    Error Power Ratio) below −51 dB. The simulated predistortion results showed that the MBM can improve the compensation of distortion in the adjacent channel of 5.8 dB and 5.7 dB compared to a memory polynomial predistorter (MPPD). The predistortion performance in the time domain showed an NMSE...... behavioral model capable of an improved performance when used for the modeling and predistortion of RF PAs deployed in ET transceivers. The proposed solution consists in a 2D behavioral model having as a dual-input the PA complex baseband envelope and the modulated supply waveform, peculiar of the ET case....... The model definition is based on binomial series, hence the name of memory binomial model (MBM). The MBM is here applied to measured data-sets acquired from an ET measurement set-up. When used as a PA model the MBM showed an NMSE (Normalized Mean Squared Error) as low as −40dB and an ACEPR (Adjacent Channel...

  19. The weighted log-rank class under truncated binomial design: saddlepoint p-values and confidence intervals.

    Science.gov (United States)

    Abd-Elfattah, Ehab F

    2012-04-01

    The randomization design used to collect the data provides basis for the exact distributions of the permutation tests. The truncated binomial design is one of the commonly used designs for forcing balance in clinical trials to eliminate experimental bias. In this article, we consider the exact distribution of the weighted log-rank class of tests for censored data under the truncated binomial design. A double saddlepoint approximation for p-values of this class is derived under the truncated binomial design. The speed and accuracy of the saddlepoint approximation over the normal asymptotic facilitate the inversion of the weighted log-rank tests to determine nominal 95% confidence intervals for treatment effect with right censored data.

  20. Quantitative binomial distribution analyses of nanoscale like-solute atom clustering and segregation in atom probe tomography data.

    Science.gov (United States)

    Moody, Michael P; Stephenson, Leigh T; Ceguerra, Anna V; Ringer, Simon P

    2008-07-01

    The applicability of the binomial frequency distribution is outlined for the analysis of the evolution nanoscale atomic clustering of dilute solute in an alloy subject to thermal ageing in 3D atom probe data. The conventional chi(2) statistics and significance testing are demonstrated to be inappropriate for comparison of quantity of solute segregation present in two or more different sized system. Pearson coefficient, mu, is shown to normalize chi(2) with respect to sample size over an order of magnitude. A simple computer simulation is implemented to investigate the binomial analysis and infer meaning in the measured value of mu over a series of systems at different solute concentrations and degree of clustering. The simulations replicate the form of experimental data and demonstrate the effect of detector efficiency to significantly underestimate the measured segregation. The binomial analysis is applied to experimental atom probe data sets and complementary simulations are used to interpret the results.

  1. A distribución binomial como ferramenta na resolución de problemas de xenética.

    OpenAIRE

    Ron Pedreira, Antonio Miguel de; Martínez, Ana María

    1999-01-01

    La distribución binomial presenta una amplia gama de campos de aplicación debido a que en situaciones cotidianas, se presenta con elevada frecuencia algún tipo de situación basada en dos hechos diferentes, alternativos, excluyentes y con probablilidades que suman 1 (cien por cien), es decir, el hecho cierto. En cuanto a la genética, pueden encontrarse supuestos que permitan la aplicación de la distribución binomial en ámbitos de la genética molecular, mendeliana, cuantitativa y genética de po...

  2. A distribución binomial como ferramenta na resolución de problemas de xenética.

    OpenAIRE

    Ron Pedreira, Antonio Miguel de; Martínez, Ana María

    1999-01-01

    La distribución binomial presenta una amplia gama de campos de aplicación debido a que en situaciones cotidianas, se presenta con elevada frecuencia algún tipo de situación basada en dos hechos diferentes, alternativos, excluyentes y con probablilidades que suman 1 (cien por cien), es decir, el hecho cierto. En cuanto a la genética, pueden encontrarse supuestos que permitan la aplicación de la distribución binomial en ámbitos de la genética molecular, mendeliana, cuantitativa y genética de po...

  3. A Record Holder Female Athlete’s Train ing Loads and its Distribution in Women 400 meter Hurdle Running

    Directory of Open Access Journals (Sweden)

    Sibel DÜNDAR

    2015-07-01

    Full Text Available The purpose of this study was to investigate the effects on 400 mt characteristics of women training load used in the hurdle runnig , the distribution and performance according to the period. At this study female athlete’s, who won second place at the European Champion Clubs' Cup Competitions and had a record - breaking six times in a country, five - year training loads and degrees were investigated. In this study, athlete’s degrees an d training loads were analyzed between the years of 1982 - 1987. Atlete’s best 100m,200m,400m,400m hurdle degrees and some training loads (sprint, andurance, weight lifting were assessed by the means and satandart deviations. Athlete’s sprint and training l oads mean and standard deviation values were calculated as 100 m ( 11.96 ± 0.17 , 200m ( 25.0 ± 0.38 , 400m ( 56.07 ± 0.91 and 400 m hurdle running ( 60.38 ± 1.88 and for the training loads of 0 - 150 m sprint ( 66.85 ± 18.95 m, endurance ( 2 02.55 ± 57.56 miles and weightlifting( 151.88 ± 68.2 tons. It was observed that percentage of change of the value of training loads and the running performance changes were not increase at the same rate. Regarding the relationship between the best run ning degree and training load, it was found a significant relationship between only 60 m sprint and 150 - 450 m sprint degrees.

  4. Potential Strategies to Address the Major Clinical Hurdles Facing Stem Cell Regenerative Therapy for Cardiovascular Disease: A Review

    Science.gov (United States)

    Nguyen, Patricia K.; Neofytou, Evgenios; Rhee, June-Wha; Wu, Joseph C.

    2017-01-01

    Importance While progress continues to be made in the field of stem cell regenerative medicine for the treatment of cardiovascular disease, significant barriers to clinical translation still exist that have thwarted the delivery of cell therapy to the bedside. Objective The purpose of this review is to summarize the major current hurdles for the clinical implementation of stem cell therapy and discuss potential strategies to overcome them. Evidence Review Information for this review was obtained through a search of PubMed and the Cochrane database for English language studies published between January 1, 2000 and June 15, 2016. Ten randomized clinical trials and eight systematic reviews were included in this review. Findings One of the major clinical hurdles facing the routine implementation of stem cell therapy is the limited and inconsistent benefit observed thus far. Reasons for this are unclear but may be due to poor cell retention and survival, as suggested by numerous preclinical studies and a handful of human studies incorporating cell fate imaging. Additional cell fate imaging studies in humans are needed to determine how these factors contribute to limited efficacy. Treatment strategies to address poor cell retention and survival are under investigation and include the following: 1) co-administering of immunosuppressive and pro-survival agents, 2) delivering cardioprotective factors packaged in exosomes rather than the cells themselves, and 3) using tissue engineering strategies to provide structural support for cells. If larger grafts are achieved using the aforementioned strategies, it will be imperative to carefully monitor the potential risks of tumorigenicity, immunogenicity, and arrhythmogenicity. Conclusions and Relevance Despite important achievements to date, stem cell therapy is not yet ready for routine clinical implementation. Significant research is still needed to address the clinical hurdles outlined herein before the next wave of large

  5. Temporary disaster debris management site identification using binomial cluster analysis and GIS.

    Science.gov (United States)

    Grzeda, Stanislaw; Mazzuchi, Thomas A; Sarkani, Shahram

    2014-04-01

    An essential component of disaster planning and preparation is the identification and selection of temporary disaster debris management sites (DMS). However, since DMS identification is a complex process involving numerous variable constraints, many regional, county and municipal jurisdictions initiate this process during the post-disaster response and recovery phases, typically a period of severely stressed resources. Hence, a pre-disaster approach in identifying the most likely sites based on the number of locational constraints would significantly contribute to disaster debris management planning. As disasters vary in their nature, location and extent, an effective approach must facilitate scalability, flexibility and adaptability to variable local requirements, while also being generalisable to other regions and geographical extents. This study demonstrates the use of binomial cluster analysis in potential DMS identification in a case study conducted in Hamilton County, Indiana.

  6. The Compound Binomial Risk Model with Randomly Charging Premiums and Paying Dividends to Shareholders

    Directory of Open Access Journals (Sweden)

    Xiong Wang

    2013-01-01

    Full Text Available Based on characteristics of the nonlife joint-stock insurance company, this paper presents a compound binomial risk model that randomizes the premium income on unit time and sets the threshold for paying dividends to shareholders. In this model, the insurance company obtains the insurance policy in unit time with probability and pays dividends to shareholders with probability when the surplus is no less than . We then derive the recursive formulas of the expected discounted penalty function and the asymptotic estimate for it. And we will derive the recursive formulas and asymptotic estimates for the ruin probability and the distribution function of the deficit at ruin. The numerical examples have been shown to illustrate the accuracy of the asymptotic estimations.

  7. Correlation functions of XX0 Heisenberg chain, q-binomial determinants, and random walks

    Energy Technology Data Exchange (ETDEWEB)

    Bogoliubov, N.M.; Malyshev, C.

    2014-02-15

    The XX0 Heisenberg model on a cyclic chain is considered. The representation of the Bethe wave functions via the Schur functions allows to apply the well-developed theory of the symmetric functions to the calculation of the thermal correlation functions. The determinantal expressions of the form-factors and of the thermal correlation functions are obtained. The q-binomial determinants enable the connection of the form-factors with the generating functions both of boxed plane partitions and of self-avoiding lattice paths. The asymptotical behavior of the thermal correlation functions is studied in the limit of low temperature provided that the characteristic parameters of the system are large enough.

  8. Correlation Functions of XX0 Heisenberg Chain, q-Binomial Determinants, and Random Walks

    CERN Document Server

    Bogoliubov, N M

    2014-01-01

    The XX0 Heisenberg model on a cyclic chain is considered. The representation of the Bethe wave functions via the Schur functions allows to apply the well-developed theory of the symmetric functions to the calculation of the thermal correlation functions. The determinantal expressions of the form-factors and of the thermal correlation functions are obtained. The q-binomial determinants enable the connection of the form-factors with the generating functions both of boxed plane partitions and of self-avoiding lattice paths. The asymptotical behavior of the thermal correlation functions is studied in the limit of low temperature provided that the characteristic parameters of the system are large enough.

  9. Assessing the Option to Abandon an Investment Project by the Binomial Options Pricing Model

    Directory of Open Access Journals (Sweden)

    Salvador Cruz Rambaud

    2016-01-01

    Full Text Available Usually, traditional methods for investment project appraisal such as the net present value (hereinafter NPV do not incorporate in their values the operational flexibility offered by including a real option included in the project. In this paper, real options, and more specifically the option to abandon, are analysed as a complement to cash flow sequence which quantifies the project. In this way, by considering the existing analogy with financial options, a mathematical expression is derived by using the binomial options pricing model. This methodology provides the value of the option to abandon the project within one, two, and in general n periods. Therefore, this paper aims to be a useful tool in determining the value of the option to abandon according to its residual value, thus making easier the control of the uncertainty element within the project.

  10. Some irreducibility and indecomposability results for truncated binomial polynomials of small degree

    Indian Academy of Sciences (India)

    2017-02-01

    In this paper, we show that the truncated binomial polynomials defined by $P_{n, k}(x)=\\sum^k_{j=0}({n\\choose j})x^j$ are irreducible for each $k\\leq 6$ and every $n\\geq k+2$. Under the same assumption $n\\geq k+2$, we also show that the polynomial $P_{n, k}$ cannot be expressed as a composition $P_{n, k}(x)=g(h(x))$ with $g\\in\\mathbb{Q}[x]$ of degree at least 2 and a quadratic polynomial $h\\in\\mathbb{Q}[x]$. Finally, we show that for $k\\geq 2$ and $m, n\\geq k+1$ the roots of the polynomial $P_{m, k}$ cannot be obtained from the roots of $P_{n, k}$, where $m\

  11. Binomial moments of the distance distribution and the probability of undetected error

    Energy Technology Data Exchange (ETDEWEB)

    Barg, A. [Lucent Technologies, Murray Hill, NJ (United States). Bell Labs.; Ashikhmin, A. [Los Alamos National Lab., NM (United States)

    1998-09-01

    In [1] K.A.S. Abdel-Ghaffar derives a lower bound on the probability of undetected error for unrestricted codes. The proof relies implicitly on the binomial moments of the distance distribution of the code. The authors use the fact that these moments count the size of subcodes of the code to give a very simple proof of the bound in [1] by showing that it is essentially equivalent to the Singleton bound. They discuss some combinatorial connections revealed by this proof. They also discuss some improvements of this bound. Finally, they analyze asymptotics. They show that an upper bound on the undetected error exponent that corresponds to the bound of [1] improves known bounds on this function.

  12. Binomial Proportion Estimation in Longitudinal Data with Non-ignorable Non-response

    Institute of Scientific and Technical Information of China (English)

    Xue-li WANG

    2013-01-01

    Non-random missing data poses serious problems in longitudinal studies.The binomial distribution parameter becomes to be unidentifiable without any other auxiliary information or assumption when it suffers from ignorable missing data.Existing methods are mostly based on the log-linear regression model.In this article,a model is proposed for longitudinal data with non-ignorable non-response.It is considered to use the pre-test baseline data to improve the identifiability of the post-test parameter.Furthermore,we derive the identified estimation (IE),the maximum likelihood estimation (MLE) and its associated variance for the posttest parameter.The simulation study based on the model of this paper shows that the proposed approach gives promising results.

  13. A comparison of LMC and SDL complexity measures on binomial distributions

    Science.gov (United States)

    Piqueira, José Roberto C.

    2016-02-01

    The concept of complexity has been widely discussed in the last forty years, with a lot of thinking contributions coming from all areas of the human knowledge, including Philosophy, Linguistics, History, Biology, Physics, Chemistry and many others, with mathematicians trying to give a rigorous view of it. In this sense, thermodynamics meets information theory and, by using the entropy definition, López-Ruiz, Mancini and Calbet proposed a definition for complexity that is referred as LMC measure. Shiner, Davison and Landsberg, by slightly changing the LMC definition, proposed the SDL measure and the both, LMC and SDL, are satisfactory to measure complexity for a lot of problems. Here, SDL and LMC measures are applied to the case of a binomial probability distribution, trying to clarify how the length of the data set implies complexity and how the success probability of the repeated trials determines how complex the whole set is.

  14. Symmetric deformed binomial distributions: An analytical example where the Boltzmann-Gibbs entropy is not extensive

    Science.gov (United States)

    Bergeron, H.; Curado, E. M. F.; Gazeau, J. P.; Rodrigues, Ligia M. C. S.

    2016-02-01

    Asymptotic behavior (with respect to the number of trials) of symmetric generalizations of binomial distributions and their related entropies is studied through three examples. The first one has the q-exponential as the generating function, the second one involves the modified Abel polynomials, and the third one has Hermite polynomials. We prove analytically that the Rényi entropy is extensive for these three cases, i.e., it is proportional (asymptotically) to the number n of events and that q-exponential and Hermite cases have also extensive Boltzmann-Gibbs. The Abel case is exceptional in the sense that its Boltzmann-Gibbs entropy is not extensive and behaves asymptotically as the square root of n. This result is obtained numerically and also confirmed analytically, under reasonable assumptions, by using a regularization of the beta function and its derivative. Probabilistic urn and genetic models are presented for illustrating this remarkable case.

  15. Generalized binomial τ-leap method for biochemical kinetics incorporating both delay and intrinsic noise

    Science.gov (United States)

    Leier, André; Marquez-Lago, Tatiana T.; Burrage, Kevin

    2008-05-01

    The delay stochastic simulation algorithm (DSSA) by Barrio et al. [Plos Comput. Biol. 2, 117(E) (2006)] was developed to simulate delayed processes in cell biology in the presence of intrinsic noise, that is, when there are small-to-moderate numbers of certain key molecules present in a chemical reaction system. These delayed processes can faithfully represent complex interactions and mechanisms that imply a number of spatiotemporal processes often not explicitly modeled such as transcription and translation, basic in the modeling of cell signaling pathways. However, for systems with widely varying reaction rate constants or large numbers of molecules, the simulation time steps of both the stochastic simulation algorithm (SSA) and the DSSA can become very small causing considerable computational overheads. In order to overcome the limit of small step sizes, various τ-leap strategies have been suggested for improving computational performance of the SSA. In this paper, we present a binomial τ-DSSA method that extends the τ-leap idea to the delay setting and avoids drawing insufficient numbers of reactions, a common shortcoming of existing binomial τ-leap methods that becomes evident when dealing with complex chemical interactions. The resulting inaccuracies are most evident in the delayed case, even when considering reaction products as potential reactants within the same time step in which they are produced. Moreover, we extend the framework to account for multicellular systems with different degrees of intercellular communication. We apply these ideas to two important genetic regulatory models, namely, the hes1 gene, implicated as a molecular clock, and a Her1/Her 7 model for coupled oscillating cells.

  16. An algorithm for sequential tail value at risk for path-independent payoffs in a binomial tree

    NARCIS (Netherlands)

    Roorda, Berend

    2010-01-01

    We present an algorithm that determines Sequential Tail Value at Risk (STVaR) for path-independent payoffs in a binomial tree. STVaR is a dynamic version of Tail-Value-at-Risk (TVaR) characterized by the property that risk levels at any moment must be in the range of risk levels later on. The algori

  17. Development of a binomial sampling plan for the carob moth (Lepidoptera: Pyralidae), a pest of California dates.

    Science.gov (United States)

    Park, Jung-Joon; Perring, Thomas M

    2010-08-01

    The seasonal density fluctuations of the carob moth, Ectomyelois ceratoniae (Zeller) (Lepidoptera: Pyralidae), were determined in a commercial date, Phoenix dactylifera L. garden. Four fruit categories (axil, ground, abscised green, and abscised brown) were sampled, and two carob moth life stages, eggs and immatures (larvae and pupae combined), were evaluated on these fruits. Based on the relative consistency of these eight sampling units (four fruit categories and two carob moth stages), four were used for the development of a binomial sampling plan. The average number of carob moth eggs and immatures on ground and abscised brown fruit was estimated from the proportion of infested fruit, and these binomial models were evaluated for model fitness and precision. These analyses suggested that the best sampling plan should consist of abscised brown dates and carob moth immatures by using a sample size of 100 dates. The performance of this binomial plan was evaluated further using a resampling protocol with 25 independent data sets at action thresholds of 7, 10, and 15% to represent light, medium and severe infestations, respectively. Results from the resampling program suggested that increasing sample size from 100 to 150 dates improved the precision of the binomial sampling plan. Use of this sampling plan will be the cornerstone of an integrated pest management program for carob moth in dates.

  18. The Effects of Violating the Beta-Binomial Assumption on Huynh's Estimates of Decision Consistency for Mastery Tests.

    Science.gov (United States)

    Johnston, Shirley H.; And Others

    A computer simulation was undertaken to determine the effects of using Huynh's single-administration estimates of the decision consistency indices for agreement and coefficient kappa, under conditions that violated the beta-binomial assumption. Included in the investigation were two unimodal score distributions that fit the model and two bimodal…

  19. Revelation of shrunken or stretched binomial dispersion and public perception of situations which might spread AIDS or HIV

    Directory of Open Access Journals (Sweden)

    Ramalingam Shanmugam

    2014-04-01

    Results: In the survey data about how AIDS/HIV might spread according to fifty respondents in thirteen nations, the functional balance exists only in three cases: and ldquo;needle and rdquo;, and ldquo;blood and rdquo; and and ldquo;sex and rdquo; justifying using the usual binomial model (1. In all other seven cases: and ldquo;glass and rdquo;, and ldquo;eating and rdquo;, and ldquo;object and rdquo;, and ldquo;toilet and rdquo;, and ldquo;hands and rdquo;, and ldquo;kissing and rdquo;, and and ldquo;care and rdquo; of an AIDS or HIV patient, there is a significant imbalance between the dispersion and its functional equivalence in terms of the mean suggesting that the new binomial called imbalanced binomial distribution (6 of this article should be used. The statistical power of this methodology is indeed excellent and hence the practitioners should make use of it. Conclusion: The new model called imbalanced binomial distribution (6 of this article is versatile enough to be useful in other research topics in the disciplines such as medicine, drug assessment, clinical trial outcomes, business, marketing, finance, economics, engineering and public health. [Int J Res Med Sci 2014; 2(2.000: 462-467

  20. The Explicit Identities for Spectral Norms of Circulant-Type Matrices Involving Binomial Coefficients and Harmonic Numbers

    Directory of Open Access Journals (Sweden)

    Jianwei Zhou

    2014-01-01

    Full Text Available The explicit formulae of spectral norms for circulant-type matrices are investigated; the matrices are circulant matrix, skew-circulant matrix, and g-circulant matrix, respectively. The entries are products of binomial coefficients with harmonic numbers. Explicit identities for these spectral norms are obtained. Employing these approaches, some numerical tests are listed to verify the results.

  1. The Beta-Binomial Distribution for Estimating the Number of False Rejections in Microarray Gene Expression Studies.

    Science.gov (United States)

    Hunt, Daniel L; Cheng, Cheng; Pounds, Stanley

    2009-03-15

    In differential expression analysis of microarray data, it is common to assume independence among null hypotheses (and thus gene expression levels). The independence assumption implies that the number of false rejections V follows a binomial distribution and leads to an estimator of the empirical false discovery rate (eFDR). The number of false rejections V is modeled with the beta-binomial distribution. An estimator of the beta-binomial false discovery rate (bbFDR) is then derived. This approach accounts for how the correlation among non-differentially expressed genes influences the distribution of V. Permutations are used to generate the observed values for V under the null hypotheses and a beta-binomial distribution is fit to the values of V. The bbFDR estimator is compared to the eFDR estimator in simulation studies of correlated non-differentially expressed genes and is found to outperform the eFDR for certain scenarios. As an example, this method is also used to perform an analysis that compares the gene expression of soft tissue sarcoma samples to normal tissue samples.

  2. Weighted profile likelihood-based confidence interval for the difference between two proportions with paired binomial data.

    Science.gov (United States)

    Pradhan, Vivek; Saha, Krishna K; Banerjee, Tathagata; Evans, John C

    2014-07-30

    Inference on the difference between two binomial proportions in the paired binomial setting is often an important problem in many biomedical investigations. Tang et al. (2010, Statistics in Medicine) discussed six methods to construct confidence intervals (henceforth, we abbreviate it as CI) for the difference between two proportions in paired binomial setting using method of variance estimates recovery. In this article, we propose weighted profile likelihood-based CIs for the difference between proportions of a paired binomial distribution. However, instead of the usual likelihood, we use weighted likelihood that is essentially making adjustments to the cell frequencies of a 2 × 2 table in the spirit of Agresti and Min (2005, Statistics in Medicine). We then conduct numerical studies to compare the performances of the proposed CIs with that of Tang et al. and Agresti and Min in terms of coverage probabilities and expected lengths. Our numerical study clearly indicates that the weighted profile likelihood-based intervals and Jeffreys interval (cf. Tang et al.) are superior in terms of achieving the nominal level, and in terms of expected lengths, they are competitive. Finally, we illustrate the use of the proposed CIs with real-life examples.

  3. Clearing up the hazy road from bench to bedside: A framework for integrating the fourth hurdle into translational medicine

    Directory of Open Access Journals (Sweden)

    John Jürgen H

    2008-09-01

    Full Text Available Abstract Background New products evolving from research and development can only be translated to medical practice on a large scale if they are reimbursed by third-party payers. Yet the decision processes regarding reimbursement are highly complex and internationally heterogeneous. This study develops a process-oriented framework for monitoring these so-called fourth hurdle procedures in the context of product development from bench to bedside. The framework is suitable both for new drugs and other medical technologies. Methods The study is based on expert interviews and literature searches, as well as an analysis of 47 websites of coverage decision-makers in England, Germany and the USA. Results Eight key steps for monitoring fourth hurdle procedures from a company perspective were determined: entering the scope of a healthcare payer; trigger of decision process; assessment; appraisal; setting level of reimbursement; establishing rules for service provision; formal and informal participation; and publication of the decision and supplementary information. Details are given for the English National Institute for Health and Clinical Excellence, the German Federal Joint Committee, Medicare's National and Local Coverage Determinations, and for Blue Cross Blue Shield companies. Conclusion Coverage determination decisions for new procedures tend to be less formalized than for novel drugs. The analysis of coverage procedures and requirements shows that the proof of patient benefit is essential. Cost-effectiveness is likely to gain importance in future.

  4. 跨栏跑教学中的恐惧心理及教学对策%The Fear Psychology in Hurdle Race Teaching and Teaching Countermeasures

    Institute of Scientific and Technical Information of China (English)

    杨胜魁

    2016-01-01

    跨栏跑是田径教学训练的重要组成部分,是发展速度、力量、柔韧、灵敏和协调的重要手段。然而,在学习跨栏跑的过程中,学生出现的恐惧心理阻碍了跨栏技术的掌握和跨栏成绩的提高,因此,人们积极探求跨栏跑恐惧心理出现的原因并努力研究克服跨栏跑恐惧心理的方式方法。结果表明,物理手段和心理学手段在跨栏跑教学中克服恐惧心理起着重要作用,在教学训练实践中合理的综合利用这两种方法,可以达到事半功倍的效果,从而克服跨栏跑恐惧心理,提高学生学习跨栏技术的积极性和主动性,促进学生身心全面发展,实现教育教学目标。%Hurdle race is an important part of track and field teaching and training,and it is an important means to develop speed,strength,flexibility,sensitivity and coordination.However,in the process of learning hurdle race,students’ fear psychology hinders their mastery of hurdles techniques and improvement of hurdles performance.Therefore,people are eager to explore the cause of hurdle race fear and try to find ways to overcome the fear of hurdle race.The results show that physical and psychological means play important roles in overcoming fear psychology in hurdle race teaching.In teaching and training practice,reasonable and comprehensive utilization of these two kinds of methods may achieve double result with half effort,overcome hurdle race fear, improve students 'learning initiative and enthusiasm of learning hurdles techniques,promote comprehensive physical and mental development of students and realize the goal of teaching and education.

  5. PREDICTIVE CONTRIBUTION OF MORPHOLOGICAL CHARACTERISTICS AND MOTOR ABILITIES ON THE RESULT OF RUNNING THE 60m HURDLES IN BOYS AGED 12 - 13 YEARS

    Directory of Open Access Journals (Sweden)

    Zana Bujak

    2014-06-01

    Full Text Available The subject of this study is to determine predictive contributions of morphological characteristics and motor abilities on the 60m hurdles, with an aim to form a group of easily applicable field tests so as to identify boys who are talented in hurdl e racing . The subject sample of this study was comprised of 60 boys aged 12 - 13. The variable sample consisted of a 60m hurdles criterion variable and a set of 13 p re dictor variables comprising of morphological characteristics, speed - strength abilities and the subjects' coordina tion qualities . Applying the regression analysis , the predictive contribution of a complete variable s et of morpholog ical characteristics and motor abilities was determined as an above average statistical significance, influencing 60m hurdle outcome. The greatest individual statistically significant predictive contribution was achieved by the variables of speed - strength quality assessment: 20m flying start r ace result with a standing long jump; and only one variable from the field of morphological characteristics: the shin length. The results support the following conclusion: the two specific variables of speed - strength quality, and 20m flying start race results along with standing long jump , can be relevant predictors of successful outcome in hurdle races .

  6. Fitness Research on Athletes of 400m Hurdles%400米栏运动员身体素质研究综述

    Institute of Scientific and Technical Information of China (English)

    周丹丹

    2011-01-01

    400 meter hurdles running campaign proved their athletic performance depends on speed,speed endurance levels,and over the hurdle technology and skills to master the rhythm between hurdles.The athletes have to master the advanced technology with personal characteristics,must be synchronized or even give priority to the development of physical fitness.%400米栏跑的运动实践证明,其运动成绩决定于速度、速度耐力水平以及过栏技术与栏间节奏的掌握技巧,而运动员要掌握具有个人特点的先进技术,必须同步甚至优先发展身体素质。

  7. Within-plant distribution and binomial sampling of Pentalonia nigronervosa (Hemiptera: Aphididae) on banana.

    Science.gov (United States)

    Robson, Jacqueline D; Wright, Mark G; Almeida, Rodrigo P P

    2006-12-01

    The banana aphid, Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae), infests banana (Musa spp.) worldwide. Pentalonia nigronervosa is the vector of Banana bunchy top virus (family Nanoviridae, genus Babuvirus) the etiological agent of Banana bunchy top disease (BBTD). BBTD is currently the most serious problem affecting banana in Hawaii. Despite the importance of this vector species, little is known about its biology or ecology. There are also no sampling plans available for P. nigronervosa. We conducted field surveys to develop a sampling plan for this pest. Ten plots were surveyed on seven commercial banana farms on the island of Oahu, HI, for the presence of P. nigronervosa on banana plantlets. We found aphids more frequently near the base of plants, followed by the newest unfurled leaf at the top of the plant. Aphids were least likely to be located on leaves in between the top and bottom of the plant. Aphid infestation on surveyed plots ranged from 8 to 95%. We developed a sequential binomial sampling plan based on our surveys. We also discovered that the within-plant distribution of P. nigronervosa is an important factor to consider when sampling for this pest. Our sampling plan will assist in the development of sustainable management practices for banana production.

  8. The binomial work-health in the transit of Curitiba city.

    Science.gov (United States)

    Tokars, Eunice; Moro, Antonio Renato Pereira; Cruz, Roberto Moraes

    2012-01-01

    The working activity in traffic of the big cities complex interacts with the environment is often in unsafe and unhealthy imbalance favoring the binomial work - health. The aim of this paper was to analyze the relationship between work and health of taxi drivers in Curitiba, Brazil. This cross-sectional observational study with 206 individuals used a questionnaire on the organization's profile and perception of the environment and direct observation of work. It was found that the majority are male, aged between 26 and 49 years and has a high school degree. They are sedentary, like making a journey from 8 to 12 hours. They consider a stressful profession, related low back pain and are concerned about safety and accidents. 40% are smokers and consume alcoholic drink and 65% do not have or do not use devices of comfort. Risk factors present in the daily taxi constraints cause physical, cognitive and organizational and can affect your performance. It is concluded that the taxi drivers must change the unhealthy lifestyle, requiring a more efficient management of government authorities for this work is healthy and safe for all involved.

  9. Vascular structure and binomial statistics for response modeling in radiosurgery of cerebral arteriovenous malformations

    Energy Technology Data Exchange (ETDEWEB)

    Andisheh, Bahram; Mavroidis, Panayiotis; Brahme, Anders; Lind, Bengt K [Department of Medical Radiation Physics, Karolinska Institutet and Stockholm University, Stockholm (Sweden); Bitaraf, Mohammad A [Department of Neurosurgery, Tehran University of Medical Sciences and Iran Gamma Knife Center, Tehran (Iran, Islamic Republic of)

    2010-04-07

    Radiation treatment of arteriovenous malformations (AVMs) has a slow and progressive vaso-occlusive effect. Some studies suggested the possible role of vascular structure in this process. A detailed biomathematical model has been used, where the morphological, biophysical and hemodynamic characteristics of intracranial AVM vessels are faithfully reproduced. The effect of radiation on plexiform and fistulous AVM nidus vessels was simulated using this theoretical model. The similarities between vascular and electrical networks were used to construct this biomathematical AVM model and provide an accurate rendering of transnidal and intranidal hemodynamics. The response of different vessels to radiation and their obliteration probability as a function of different angiostructures were simulated and total obliteration was defined as the probability of obliteration of all possible vascular pathways. The dose response of the whole AVM is observed to depend on the vascular structure of the intra-nidus AVM. Furthermore, a plexiform AVM appears to be more prone to obliteration compared with an AVM of the same size but having more arteriovenous fistulas. Finally, a binomial model was introduced, which considers the number of crucial vessels and is able to predict the dose response behavior of AVMs with a complex vascular structure.

  10. Binomial Markov-Switching Multifractal model with Skewed t innovations and applications to Chinese SSEC Index

    Science.gov (United States)

    Liu, Yufang; Zhang, Weiguo; Fu, Junhui

    2016-11-01

    This paper presents the Binomial Markov-switching Multifractal (BMSM) model of asset returns with Skewed t innovations (BMSM-Skewed t for short), which considers the fat tails, skewness and multifractality in asset returns simultaneously. The parameters of BMSM-Skewed t model can be estimated by Maximum Likelihood (ML) methods, and volatility forecasting can be accomplished via Bayesian updating. In order to evaluate the performance of BMSM-Skewed t model, BMSM model with Normal innovations (BMSM-N), BMSM model with Student-t innovations (BMSM-t) and GARCH(1,1) models (GARCH-N, GARCH-t and GARCH-Skewed t) are chosen for comparison. Through empirical studies on Shanghai Stock Exchange Composite Index (SSEC), we find that for sample estimation, BMSM models outperform the GARCH(1,1) models through BIC and AIC rules, and BMSM-Skewed t performs the best among all the models due to its fat tails, skewness and multifractality. In addition, BMSM-Skewed t model dominates other models at most forecasting horizons for out-of-sample volatility forecasts in terms of MSE, MAE and SPA test.

  11. Binomial Distribution Sample Confidence Intervals Estimation 7. Absolute Risk Reduction and ARR-like Expressions

    Directory of Open Access Journals (Sweden)

    Andrei ACHIMAŞ CADARIU

    2004-08-01

    Full Text Available Assessments of a controlled clinical trial suppose to interpret some key parameters as the controlled event rate, experimental event date, relative risk, absolute risk reduction, relative risk reduction, number needed to treat when the effect of the treatment are dichotomous variables. Defined as the difference in the event rate between treatment and control groups, the absolute risk reduction is the parameter that allowed computing the number needed to treat. The absolute risk reduction is compute when the experimental treatment reduces the risk for an undesirable outcome/event. In medical literature when the absolute risk reduction is report with its confidence intervals, the method used is the asymptotic one, even if it is well know that may be inadequate. The aim of this paper is to introduce and assess nine methods of computing confidence intervals for absolute risk reduction and absolute risk reduction – like function.Computer implementations of the methods use the PHP language. Methods comparison uses the experimental errors, the standard deviations, and the deviation relative to the imposed significance level for specified sample sizes. Six methods of computing confidence intervals for absolute risk reduction and absolute risk reduction-like functions were assessed using random binomial variables and random sample sizes.The experiments shows that the ADAC, and ADAC1 methods obtains the best overall performance of computing confidence intervals for absolute risk reduction.

  12. Binomial Test Method for Determining Probability of Detection Capability for Fracture Critical Applications

    Science.gov (United States)

    Generazio, Edward R.

    2011-01-01

    The capability of an inspection system is established by applications of various methodologies to determine the probability of detection (POD). One accepted metric of an adequate inspection system is that for a minimum flaw size and all greater flaw sizes, there is 0.90 probability of detection with 95% confidence (90/95 POD). Directed design of experiments for probability of detection (DOEPOD) has been developed to provide an efficient and accurate methodology that yields estimates of POD and confidence bounds for both Hit-Miss or signal amplitude testing, where signal amplitudes are reduced to Hit-Miss by using a signal threshold Directed DOEPOD uses a nonparametric approach for the analysis or inspection data that does require any assumptions about the particular functional form of a POD function. The DOEPOD procedure identifies, for a given sample set whether or not the minimum requirement of 0.90 probability of detection with 95% confidence is demonstrated for a minimum flaw size and for all greater flaw sizes (90/95 POD). The DOEPOD procedures are sequentially executed in order to minimize the number of samples needed to demonstrate that there is a 90/95 POD lower confidence bound at a given flaw size and that the POD is monotonic for flaw sizes exceeding that 90/95 POD flaw size. The conservativeness of the DOEPOD methodology results is discussed. Validated guidelines for binomial estimation of POD for fracture critical inspection are established.

  13. Emergence of q-statistical functions in a generalized binomial distribution with strong correlations

    Science.gov (United States)

    Ruiz, G.; Tsallis, C.

    2015-05-01

    We study a symmetric generalization pk ( N ) ( η , α ) of the binomial distribution recently introduced by Bergeron et al., where η ∈ [0, 1] denotes the win probability and α is a positive parameter. This generalization is based on q-exponential generating functions ( eq gen z ≡ [ 1 + ( 1 - qgen ) z ] 1 / ( 1 - q gen ) ; e1 z = e z ) where qgen = 1 + 1/α. The numerical calculation of the probability distribution function of the number of wins k, related to the number of realizations N, strongly approaches a discrete qdisc-Gaussian distribution, for win-loss equiprobability (i.e., η = 1/2) and all values of α. Asymptotic N → ∞ distribution is in fact a qatt-Gaussian eq att - β z 2 , where qatt = 1 - 2/(α - 2) and β = (2α - 4). The behavior of the scaled quantity k/Nγ is discussed as well. For γ distribution, yielding a power law, although not exactly a qLD-exponential decay. All q-statistical parameters which emerge are univocally defined by (η, α). Finally, we discuss the analytical connection with the Pólya urn problem.

  14. Monte Carlo evaluation of the ANOVA's F and Kruskal-Wallis tests under binomial distribution

    Directory of Open Access Journals (Sweden)

    Eric Batista Ferreira

    2012-12-01

    Full Text Available To verify the equality of more than two levels of a factor under interest in experiments conducted under a completely randomized design (CRD it is common to use the F ANOVA test, which is considered the most powerful test for this purpose. However, the reliability of such results depends on the following assumptions: additivity of effects, independence, homoscedasticity and normality of the errors. The nonparametric Kruskal-Wallis test requires more moderate assumptions and therefore it is an alternative when the assumptions required by the F test are not met. However, the stronger the assumptions of a test, the better its performance. When the fundamental assumptions are met the F test is the best option. In this work, the normality of the errors is violated. Binomial response variables are simulated in order to compare the performances of the F and Kruskal-Wallis tests when one of the analysis of variance assumptions is not satisfied. Through Monte Carlo simulation, were simulated $3,150,000$ experiments to evaluate the type I error rate and power rate of the tests. In most situations, the power of the F test was superior to the Kruskal-Wallis and yet, the F test controlled the Type I error rates.

  15. The Night-Death binomial as a poetic ploy - a cross-cultural look from the graveyard poets to expressionism

    Directory of Open Access Journals (Sweden)

    Lioba Simon-Schuhmacher

    2015-11-01

    Full Text Available The essay describes the use of the Night-Death binomial and tracks its evolution from the eighteenth century to Expressionism across Great Britain, Germany, Spain, and Austria, at the hand of poems such as Edward Young’s Night Thoughts (1745, Novalis’s Hymnen an die Nacht, (1800, José Blanco White’s sonnet “Night and Death” (1828, and Georg Trakl’s “Verwandlung des Bösen” (1914. Romanticism brought along a preference for the nocturnal: night, moonlight, shades and shadows, mist and mystery, somber mood, morbidity, and death, as opposed to the Enlightenment’s predilection for day, light, clarity, and life. The essay analyses how poets from different national contexts and ages employ images and symbols of the night to create an association with death. It furthermore shows how, with varying attitudes and results, they manage to convert this binomial into a poetic ploy.

  16. EXPECTED PRESENT VALUE OF TOTAL DIVIDENDS IN THE COMPOUND BINOMIAL MODEL WITH DELAYED CLAIMS AND RANDOM INCOME

    Institute of Scientific and Technical Information of China (English)

    周杰明; 莫晓云; 欧辉; 杨向群

    2013-01-01

    In this paper, a compound binomial model with a constant dividend barrier and random income is considered. Two types of individual claims, main claims and by-claims, are defined, where every by-claim is induced by the main claim and may be delayed for one time period with a certain probability. The premium income is assumed to another binomial process to capture the uncertainty of the customer’s arrivals and payments. A system of difference equations with certain boundary conditions for the expected present value of total dividend payments prior to ruin is derived and solved. Explicit results are obtained when the claim sizes are Kn distributed or the claim size distributions have finite support. Numerical results are also provided to illustrate the impact of the delay of by-claims on the expected present value of dividends.

  17. Strong Deviation Theorems of the Binomial Distribution%关于二项分布的强偏差定理

    Institute of Scientific and Technical Information of China (English)

    王学武; 张宇超

    2011-01-01

    利用分析方法建立了用不等式表示的用渐近平均对数似然比刻划的服从二项分布的随机变量序列的强偏差定理,作为推论得到了服从二项分布的相依随机变量序列的强大数定律.%In this paper, the notion of the logarithmic likelihood ratio, as a measure of the deviation between a sequence of arbitrary random variables and a sequence of independent random variables with the binomial distribution, is introduced. Using the concept, we obtain the strong deviation theorems represented by inequalities. Meanwhile, we get the strong laws of the large numbers for the sequence of the dependent random variables obeyed the the binomial distributions.

  18. Beta-Bino mial 回归模型及其应用%Beta-Binomial Regression and Its Application

    Institute of Scientific and Technical Information of China (English)

    赵为华; 张日权

    2016-01-01

    Beta‐Binomial distribution is frequently used to describe the over‐dispersion count data in the success‐failure type test or satisfaction ratings survey problem .In this paper ,we address the Beta‐Binomial regression model ,and the maximum likelihood estimate method is investigated ,which can be implemented by the New ton‐Raphson algorithm .Furthermore ,the Score test methods are proposed to test the important covariates and the existing of the correlation parameter , and their test powers are investigated by simulations . Finally , the real data analysis is used to illustrate the usefulness of Beta‐Binomial regression model .%在成败型试验中或满意度支持率调查中,Beta‐Binomial分布常被用来刻画具有偏大离差的计数型比例数据,由此提出Beta‐Binomial回归模型,研究参数的最大似然估计方法并基于New ton‐Raphson算法给出参数估计的迭代方法;重点讨论模型中回归参数和相关性参数存在的检验问题,提出Score检验方法并通过数值模拟研究Score检验统计量的检验功效问题;实例分析证明Beta‐Binomial回归模型的有用性。

  19. Criterios sobre el uso de la distribución normal para aproximar la distribución binomial

    OpenAIRE

    Ortiz Pinilla, Jorge; Castro, Amparo; Neira, Tito; Torres, Pedro; Castañeda, Javier

    2012-01-01

    Las dos reglas empíricas más conocidas para aceptar la aproximación normal de la distribución binomial carecen de regularidad en el control del margen de error cometido al utilizar la aproximación normal. Se propone un criterio y algunas fórmulas para controlarlo cerca de algunos valores escogidos para el error máximo.

  20. Enumerative and binomial sequential sampling plans for the multicolored Asian lady beetle (Coleoptera: Coccinellidae) in wine grapes.

    Science.gov (United States)

    Galvan, T L; Burkness, E C; Hutchison, W D

    2007-06-01

    To develop a practical integrated pest management (IPM) system for the multicolored Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), in wine grapes, we assessed the spatial distribution of H. axyridis and developed eight sampling plans to estimate adult density or infestation level in grape clusters. We used 49 data sets collected from commercial vineyards in 2004 and 2005, in Minnesota and Wisconsin. Enumerative plans were developed using two precision levels (0.10 and 0.25); the six binomial plans reflected six unique action thresholds (3, 7, 12, 18, 22, and 31% of cluster samples infested with at least one H. axyridis). The spatial distribution of H. axyridis in wine grapes was aggregated, independent of cultivar and year, but it was more randomly distributed as mean density declined. The average sample number (ASN) for each sampling plan was determined using resampling software. For research purposes, an enumerative plan with a precision level of 0.10 (SE/X) resulted in a mean ASN of 546 clusters. For IPM applications, the enumerative plan with a precision level of 0.25 resulted in a mean ASN of 180 clusters. In contrast, the binomial plans resulted in much lower ASNs and provided high probabilities of arriving at correct "treat or no-treat" decisions, making these plans more efficient for IPM applications. For a tally threshold of one adult per cluster, the operating characteristic curves for the six action thresholds provided binomial sequential sampling plans with mean ASNs of only 19-26 clusters, and probabilities of making correct decisions between 83 and 96%. The benefits of the binomial sampling plans are discussed within the context of improving IPM programs for wine grapes.

  1. On Simon's two-stage design for single-arm phase IIA cancer clinical trials under beta-binomial distribution.

    Science.gov (United States)

    Liu, Junfeng; Lin, Yong; Shih, Weichung Joe

    2010-05-10

    Simon (Control. Clin. Trials 1989; 10:1-10)'s two-stage design has been broadly applied to single-arm phase IIA cancer clinical trials in order to minimize either the expected or the maximum sample size under the null hypothesis of drug inefficacy, i.e. when the pre-specified amount of improvement in response rate (RR) is not expected to be observed. This paper studies a realistic scenario where the standard and experimental treatment RRs follow two continuous distributions (e.g. beta distribution) rather than two single values. The binomial probabilities in Simon's (Control. Clin. Trials 1989; 10:1-10) design are replaced by prior predictive Beta-binomial probabilities that are the ratios of two beta functions and domain-restricted RRs involve incomplete beta functions to induce the null hypothesis acceptance probability. We illustrate that Beta-binomial mixture model based two-stage design retains certain desirable properties for hypothesis testing purpose. However, numerical results show that such designs may not exist under certain hypothesis and error rate (type I and II) setups within maximal sample size approximately 130. Furthermore, we give theoretical conditions for asymptotic two-stage design non-existence (sample size goes to infinity) in order to improve the efficiency of design search and to avoid needless searching.

  2. Joint longitudinal hurdle and time-to-event models: an application related to viral load and duration of the first treatment regimen in patients with HIV initiating therapy.

    Science.gov (United States)

    Brilleman, Samuel L; Crowther, Michael J; May, Margaret T; Gompels, Mark; Abrams, Keith R

    2016-09-10

    Shared parameter joint models provide a framework under which a longitudinal response and a time to event can be modelled simultaneously. A common assumption in shared parameter joint models has been to assume that the longitudinal response is normally distributed. In this paper, we instead propose a joint model that incorporates a two-part 'hurdle' model for the longitudinal response, motivated in part by longitudinal response data that is subject to a detection limit. The first part of the hurdle model estimates the probability that the longitudinal response is observed above the detection limit, whilst the second part of the hurdle model estimates the mean of the response conditional on having exceeded the detection limit. The time-to-event outcome is modelled using a parametric proportional hazards model, assuming a Weibull baseline hazard. We propose a novel association structure whereby the current hazard of the event is assumed to be associated with the current combined (expected) outcome from the two parts of the hurdle model. We estimate our joint model under a Bayesian framework and provide code for fitting the model using the Bayesian software Stan. We use our model to estimate the association between HIV RNA viral load, which is subject to a lower detection limit, and the hazard of stopping or modifying treatment in patients with HIV initiating antiretroviral therapy. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Hurdles in tissue engineering/regenerative medicine product commercialization: a pilot survey of governmental funding agencies and the financial industry.

    Science.gov (United States)

    Bertram, Timothy A; Tentoff, Edward; Johnson, Peter C; Tawil, Bill; Van Dyke, Mark; Hellman, Kiki B

    2012-11-01

    The Tissue Engineering and Regenerative Medicine International Society of the Americas (TERMIS-AM) Industry Committee conducted a semiquantitative opinion survey in 2010 to delineate potential hurdles to commercialization perceived by the TERMIS constituency groups that participate in the stream of technology commercialization (academia, start-up companies, development-stage companies, and established companies). A significant hurdle identified consistently by each group was access to capital for advancing potential technologies into development pathways leading to commercialization. A follow-on survey was developed by the TERMIS-AM Industry Committee to evaluate the financial industry's perspectives on investing in regenerative medical technologies. The survey, composed of 15 questions, was developed and provided to 37 investment organizations in one of three sectors (governmental, private, and public investors). The survey was anonymous and confidential with sector designation the only identifying feature of each respondent's organization. Approximately 80% of the survey was composed of respondents from the public (n=14) and private (n=15) sectors. Each respondent represents one investment organization with the potential of multiple participants participating to form the organization's response. The remaining organizations represented governmental agencies (n=8). Results from this survey indicate that a high percentage ($2MM into regenerative medical companies at the different stages of a company's life cycle. Investors recognized major hurdles to this emerging industry, including regulatory pathway, clinical translation, and reimbursement of these new products. Investments in regenerative technologies have been cyclical over the past 10-15 years, but investors recognized a 1-5-year investment period before the exit via Merger and Acquisition (M&A). Investors considered musculoskeletal products and their top technology choice with companies in the clinical stage

  4. Negative learning

    Energy Technology Data Exchange (ETDEWEB)

    Oppenheimer, M. [Woodrow Wilson School of Public and International Affairs, Department of Geosciences, Princeton University, Princeton, NJ (United States); O' Neill, B.C. [International Institute for Applied Systems Analysis, Laxenburg (Austria)]|[Institute for the Study of Society and Environment, National Center for Atmospheric Research, Boulder, CO (United States); Webster M. [MIT Joint Program on the Science and Policy of Global Change, Massachusetts Institute of Technology, Cambridge, MA (United States)

    2008-07-15

    New technical information may lead to scientific beliefs that diverge over time from the a posteriori right answer. We call this phenomenon, which is particularly problematic in the global change arena, negative learning. Negative learning may have affected policy in important cases, including stratospheric ozone depletion, dynamics of the West Antarctic ice sheet, and population and energy projections. We simulate negative learning in the context of climate change with a formal model that embeds the concept within the Bayesian framework, illustrating that it may lead to errant decisions and large welfare losses to society. Based on these cases, we suggest approaches to scientific assessment and decision making that could mitigate the problem. Application of the tools of science history to the study of learning in global change, including critical examination of the assessment process to understand how judgments are made, could provide important insights on how to improve the flow of information to policy makers.

  5. Negative Certainty

    Science.gov (United States)

    Ariso, José María

    2017-01-01

    The definitions of "negative knowledge" and the studies in this regard published to date have not considered the categorial distinction Wittgenstein established between knowledge and certainty. Hence, the important role that certainty, despite its omission, should have in these definitions and studies has not yet been shown. In this…

  6. Negative Numbers

    Science.gov (United States)

    Galbraith, Mary J.

    1974-01-01

    Examination of models for representing integers demonstrates that formal operational thought is required for establishing the operations on integers. Advocated is the use of many models for introducing negative numbers but, apart from addition, it is recommended that operations on integers be delayed until the formal operations stage. (JP)

  7. Negative Certainty

    Science.gov (United States)

    Ariso, José María

    2017-01-01

    The definitions of "negative knowledge" and the studies in this regard published to date have not considered the categorial distinction Wittgenstein established between knowledge and certainty. Hence, the important role that certainty, despite its omission, should have in these definitions and studies has not yet been shown. In this…

  8. Counting Vesicular Release Events Reveals Binomial Release Statistics at Single Glutamatergic Synapses.

    Science.gov (United States)

    Malagon, Gerardo; Miki, Takafumi; Llano, Isabel; Neher, Erwin; Marty, Alain

    2016-04-06

    Many central glutamatergic synapses contain a single presynaptic active zone and a single postsynaptic density. However, the basic functional properties of such "simple synapses" remain unclear. One important step toward understanding simple synapse function is to analyze the number of synaptic vesicles released in such structures per action potential, but this goal has remained elusive until now. Here, we describe procedures that allow reliable vesicular release counting at simple synapses between parallel fibers and molecular layer interneurons of rat cerebellar slices. Our analysis involves local extracellular stimulation of single parallel fibers and deconvolution of resulting EPSCs using quantal signals as template. We observed a reduction of quantal amplitudes (amplitude occlusion) in pairs of consecutive EPSCs due to receptor saturation. This effect is larger (62%) than previously reported and primarily reflects receptor activation rather than desensitization. In addition to activation-driven amplitude occlusion, each EPSC reduces amplitudes of subsequent events by an estimated 3% due to cumulative desensitization. Vesicular release counts at simple synapses follow binomial statistics with a maximum that varies from 2 to 10 among experiments. This maximum presumably reflects the number of docking sites at a given synapse. These results show striking similarities, as well as significant quantitative differences, with respect to previous results at simple GABAergic synapses. It is generally accepted that the output signal of individual central synapses saturates at high release probability, but it remains unclear whether the source of saturation is presynaptic, postsynaptic, or both presynaptic and postsynaptic. To clarify this and other issues concerning the function of synapses, we have developed new recording and analysis methods at single central glutamatergic synapses. We find that individual release events engage a high proportion of postsynaptic

  9. Hurdle Effect of Antimicrobial Activity Achieved by Time Differential Releasing of Nisin and Chitosan Hydrolysates from Bacterial Cellulose.

    Science.gov (United States)

    Hsiao, Hui-Ling; Lin, Shih-Bin; Chen, Li-Chen; Chen, Hui-Huang

    2016-05-01

    We investigated the combined antimicrobial effect of nisin and chitosan hydrolysates (CHs) by regulating the antimicrobial reaction order of substances due to differential releasing rate from hydroxypropylmethylcellulose-modified bacterial cellulose (HBC). The minimum inhibitory concentration of nisin against Staphylococcus aureus and that of CHs against Escherichia coli were 6 IU and 200 μg/mL, respectively. Hurdle and additive effects in antimicrobial tests were observed when nisin was used 6 h before CH treatment against S. aureus; similar effects were observed when CH was used before nisin treatment against E. coli. Simultaneously combined treatment of nisin and CHs exhibited the low antimicrobial effect. HBC was then selected as the carrier for the controlled release of nisin and CHs. A 90% inhibition in the growth of S. aureus and E. coli was achieved when 30 IU-nisin-containing HBC and 62.5 μg/mL-CH-containing HBC were used simultaneously. The controlled release of nisin and CHs by using HBC minimized the interaction between nisin and CHs as well as increased the number of microbial targets.

  10. Binomial mitotic segregation of MYCN-carrying double minutes in neuroblastoma illustrates the role of randomness in oncogene amplification.

    Directory of Open Access Journals (Sweden)

    Gisela Lundberg

    Full Text Available BACKGROUND: Amplification of the oncogene MYCN in double minutes (DMs is a common finding in neuroblastoma (NB. Because DMs lack centromeric sequences it has been unclear how NB cells retain and amplify extrachromosomal MYCN copies during tumour development. PRINCIPAL FINDINGS: We show that MYCN-carrying DMs in NB cells translocate from the nuclear interior to the periphery of the condensing chromatin at transition from interphase to prophase and are preferentially located adjacent to the telomere repeat sequences of the chromosomes throughout cell division. However, DM segregation was not affected by disruption of the telosome nucleoprotein complex and DMs readily migrated from human to murine chromatin in human/mouse cell hybrids, indicating that they do not bind to specific positional elements in human chromosomes. Scoring DM copy-numbers in ana/telophase cells revealed that DM segregation could be closely approximated by a binomial random distribution. Colony-forming assay demonstrated a strong growth-advantage for NB cells with high DM (MYCN copy-numbers, compared to NB cells with lower copy-numbers. In fact, the overall distribution of DMs in growing NB cell populations could be readily reproduced by a mathematical model assuming binomial segregation at cell division combined with a proliferative advantage for cells with high DM copy-numbers. CONCLUSION: Binomial segregation at cell division explains the high degree of MYCN copy-number variability in NB. Our findings also provide a proof-of-principle for oncogene amplification through creation of genetic diversity by random events followed by Darwinian selection.

  11. Some Large Deviation Results for Generalized Compound Binomial Risk Models%广义复合二项风险模型的若干大偏差结果

    Institute of Scientific and Technical Information of China (English)

    孔繁超; 赵朋

    2009-01-01

    This paper is a further investigation of large deviation for partial and random sums of random variables, where {X_n, n≥ 1} is non-negative independent identically distributed random variables with a common heavy-tailed distribution function F on the real line R and finite mean μ∈ R. {N(n),n≥ 0} is a binomial process with a parameter p ∈ (0, 1) and independent of {X_n,n≥1}; {M(n),n≥0} is a Poisson process with intensity λ > 0, S_n=∑~(N(n))_(i=1) X_i-cM(n). Suppose F ∈ C, we futher extend and improve some large deviation results. These results can apply to certain problems in insurance and finance.

  12. Binomial Schedule for an M/G/1 Type Queueing System with an Unreliable Server under N-Policy

    Directory of Open Access Journals (Sweden)

    Lotfi Tadj

    2014-01-01

    Full Text Available We consider in this paper an M/G/1 type queueing system with the following extensions. First, the server is unreliable and is subject to random breakdowns. Second, the server also implements the well-known N-policy. Third, instead of a Bernoulli vacation schedule, the more general notion of binomial schedule with K vacations is applied. A cost function with two decision variables is developed. A numerical example shows the effect of the system parameters on the optimal management policy.

  13. Modeling and analysis of self-similar traffic source based on fractal-binomial-noise-driven Poisson process

    Institute of Scientific and Technical Information of China (English)

    ZHANG Di; ZHANG Min; YE Pei-da

    2006-01-01

    This article explores the short-range dependence (SRD) and the long-range dependence (LRD) of self-similar traffic generated by the fractal-binomial-noise-driven Poisson process (FBNDP) model and lays emphasis on the former. By simulation, the SRD decaying trends with the increase of Hurst value and peak rate are obtained, respectively. After a comprehensive analysis of accuracy of self-similarity intensity,the optimal range of peak rate is determined by taking into account the time cost, the accuracy of self-similarity intensity,and the effect of SRD.

  14. A free gift: an adaptive strategy in a single-arm trial using an exact test through the binomial distribution.

    Science.gov (United States)

    Wang, Jin

    2012-01-01

    For medical product development within the same generation, single-arm trial designs are commonly implemented to test the performance of the new product against an objective performance criterion. When the primary endpoint is binary and the sample size is moderate, an exact test through the binomial distribution is usually used. This article shows that it is a free gift to add an adaptive component to a fixed-sample-size design so that when the interim result is marginal, the adaptive feature can be activated without any penalty. A hypothetical example is used to illustrate the application of this method.

  15. Binomial distribution-based quantitative measurement of multiple-acceptors fluorescence resonance energy transfer by partially photobleaching acceptor

    Science.gov (United States)

    Zhang, Lili; Yu, Huaina; Zhang, Jianwei; Chen, Tongsheng

    2014-06-01

    We report that binomial distribution depending on acceptor photobleaching degree can be used to characterize the proportions of various kinds of FRET (Fluorescence Resonance Energy Transfer) constructs resulted from partial acceptor photobleaching of multiple-acceptors FRET system. On this basis, we set up a rigorous quantitation theory for multiple-acceptors FRET construct named as Mb-PbFRET which is not affected by the imaging conditions and fluorophore properties. We experimentally validate Mb-PbFRET with FRET constructs consisted of one donor and two or three acceptors inside living cells on confocal and wide-field microscopes.

  16. Trojan Horse Antibiotics—A Novel Way to Circumvent Gram-Negative Bacterial Resistance?

    OpenAIRE

    Tillotson, Glenn S.

    2016-01-01

    Antibiotic resistance has been emerged as a major global health problem. In particular, gram-negative species pose a significant clinical challenge as bacteria develop or acquire more resistance mechanisms. Often, these bacteria possess multiple resistance mechanisms, thus nullifying most of the major classes of drugs. Novel approaches to this issue are urgently required. However, the challenges of developing new agents are immense. Introducing novel agents is fraught with hurdles, thus adapt...

  17. Potential, with hurdles

    Energy Technology Data Exchange (ETDEWEB)

    Feller, Gordon

    2012-11-01

    Droves of international companies have discovered the Brazilian wind energy market. But growth is limited by the high cost of generation and equipment, as well as regulatory and financing constraints.

  18. Implementation hurdles of an interactive, integrated, point-of-care computerised decision support system for hospital antibiotic prescription.

    Science.gov (United States)

    Chow, A L; Ang, A; Chow, C Z; Ng, T M; Teng, C; Ling, L M; Ang, B S; Lye, D C

    2016-02-01

    Antimicrobial stewardship is used to combat antimicrobial resistance. In Singapore, a tertiary hospital has integrated a computerised decision support system, called Antibiotic Resistance Utilisation and Surveillance-Control (ARUSC), into the electronic inpatient prescribing system. ARUSC is launched either by the physician to seek guidance for an infectious disease condition or via auto-trigger when restricted antibiotics are prescribed. This paper describes the implementation of ARUSC over three phases from 1 May 2011 to 30 April 2013, compared factors between ARUSC launches via auto-trigger and for guidance, examined factors associated with acceptance of ARUSC recommendations, and assessed user acceptability. During the study period, a monthly average of 9072 antibiotic prescriptions was made, of which 2370 (26.1%) involved ARUSC launches. Launches via auto-trigger comprised 48.1% of ARUSC launches. In phase 1, 23% of ARUSC launches were completed. This rose to 38% in phase 2, then 87% in phase 3, as escapes from the ARUSC programme were sequentially disabled. Amongst completed launches for guidance, 89% of ARUSC recommendations were accepted versus 40% amongst completed launches via auto-trigger. Amongst ARUSC launches for guidance, being from a medical department [adjusted odds ratio (aOR)=1.20, 95% confidence interval (CI) 1.04-1.37] and ARUSC launch during on-call (aOR=1.81, 95% CI 1.61-2.05) were independently associated with acceptance of ARUSC recommendations. Junior physicians found ARUSC useful. Senior physicians found ARUSC reliable but admitted to having preferences for antibiotics that may conflict with ARUSC. Hospital-wide implementation of ARUSC encountered hurdles from physicians. With modifications, the completion rate improved.

  19. Comparison of robustness to outliers between robust poisson models and log-binomial models when estimating relative risks for common binary outcomes: a simulation study.

    Science.gov (United States)

    Chen, Wansu; Shi, Jiaxiao; Qian, Lei; Azen, Stanley P

    2014-06-26

    To estimate relative risks or risk ratios for common binary outcomes, the most popular model-based methods are the robust (also known as modified) Poisson and the log-binomial regression. Of the two methods, it is believed that the log-binomial regression yields more efficient estimators because it is maximum likelihood based, while the robust Poisson model may be less affected by outliers. Evidence to support the robustness of robust Poisson models in comparison with log-binomial models is very limited. In this study a simulation was conducted to evaluate the performance of the two methods in several scenarios where outliers existed. The findings indicate that for data coming from a population where the relationship between the outcome and the covariate was in a simple form (e.g. log-linear), the two models yielded comparable biases and mean square errors. However, if the true relationship contained a higher order term, the robust Poisson models consistently outperformed the log-binomial models even when the level of contamination is low. The robust Poisson models are more robust (or less sensitive) to outliers compared to the log-binomial models when estimating relative risks or risk ratios for common binary outcomes. Users should be aware of the limitations when choosing appropriate models to estimate relative risks or risk ratios.

  20. Interrelationships Between Receiver/Relative Operating Characteristics Display, Binomial, Logit, and Bayes' Rule Probability of Detection Methodologies

    Science.gov (United States)

    Generazio, Edward R.

    2014-01-01

    Unknown risks are introduced into failure critical systems when probability of detection (POD) capabilities are accepted without a complete understanding of the statistical method applied and the interpretation of the statistical results. The presence of this risk in the nondestructive evaluation (NDE) community is revealed in common statements about POD. These statements are often interpreted in a variety of ways and therefore, the very existence of the statements identifies the need for a more comprehensive understanding of POD methodologies. Statistical methodologies have data requirements to be met, procedures to be followed, and requirements for validation or demonstration of adequacy of the POD estimates. Risks are further enhanced due to the wide range of statistical methodologies used for determining the POD capability. Receiver/Relative Operating Characteristics (ROC) Display, simple binomial, logistic regression, and Bayes' rule POD methodologies are widely used in determining POD capability. This work focuses on Hit-Miss data to reveal the framework of the interrelationships between Receiver/Relative Operating Characteristics Display, simple binomial, logistic regression, and Bayes' Rule methodologies as they are applied to POD. Knowledge of these interrelationships leads to an intuitive and global understanding of the statistical data, procedural and validation requirements for establishing credible POD estimates.

  1. Studying the Hurdles of Insulin Prescription (SHIP©: development, scoring and initial validation of a new self-administered questionnaire

    Directory of Open Access Journals (Sweden)

    Yomtov Bernard

    2007-08-01

    Full Text Available Abstract Background Although insulin therapy is well-accepted by symptomatic diabetic patients, it is still often delayed in less severe patients, in whom injectable insulin remains under-used. A better understanding of patients' perception of insulin would eventually help physicians to adopt the most appropriate dialogue when having to motivate patients to initiate or to intensify insulin injection. Methods The 'Studying the Hurdles of Insulin Prescription' (SHIP questionnaire was developed based on a list of concepts derived from three diabetic patients' focus groups, and was included into two cross-sectional studies with similar design: SHIP Oral study and SHIP Premix study. Diabetic patients treated with oral hypoglycaemic agents (OHA; n = 1,494 and patients already treated with insulin (n = 1,150 completed the questionnaire at baseline, 6- and 12 months. Psychometric properties were assessed: 1 structure analysis by Principal Component Analysis (PCA with Varimax rotation, 2 internal consistency reliability (Cronbach's alpha, and 3 concurrent validity (Spearman correlation coefficients with the Fear of Self-Injecting (FSI score of the Diabetes Fear of Injecting and Self-testing Questionnaire. Reluctance/motivation towards insulin was assessed. Scores' ability to predict patients' insulin injection reluctance/motivation and initiation/intensification was evaluated with the Area Under the Receiver Operating Characteristic (ROC Curve (AUC. Results PCA analysis confirmed the structure of the 14 items grouped into 3 dimensions: 'acceptance and motivation', 'fear and constraints', and 'restraints and barriers' towards insulin injection. Internal consistency reliability was excellent (Cronbach's alpha > 0.70; concurrent validity was good. The three scores were significantly predictive of patients' reluctance/motivation towards insulin injection initiation, as they were of patients' actual switch, except for the 'restraints and barriers' dimension

  2. Education-Healthy Development Binomial from the Health of Whole Living Entity Perspective

    OpenAIRE

    Stanciu Miltiade

    2015-01-01

    Social life including economic life should evolve in harmony with live world ecology. The economy, as human society product should harmonize with the exigencies of “the health of whole living entity†. However, the realities of the present lived at local and global level reveal: inhuman social inequalities, frustrating consumerism, systemic pollution, poverty in the middle abundance, science without humanism, wealth without honest work etc. generated by negative human behaviors. The transi...

  3. Is “Hit and Run” a Single Word? The Processing of Irreversible Binomials in Neglect Dyslexia

    Science.gov (United States)

    Arcara, Giorgio; Lacaita, Graziano; Mattaloni, Elisa; Passarini, Laura; Mondini, Sara; Benincà, Paola; Semenza, Carlo

    2012-01-01

    The present study is the first neuropsychological investigation into the problem of the mental representation and processing of irreversible binomials (IBs), i.e., word pairs linked by a conjunction (e.g., “hit and run,” “dead or alive”). In order to test their lexical status, the phenomenon of neglect dyslexia is explored. People with left-sided neglect dyslexia show a clear lexical effect: they can read IBs better (i.e., by dropping the leftmost words less frequently) when their components are presented in their correct order. This may be taken as an indication that they treat these constructions as lexical, not decomposable, elements. This finding therefore constitutes strong evidence that IBs tend to be stored in the mental lexicon as a whole and that this whole form is preferably addressed in the retrieval process. PMID:22347199

  4. Type I error probability spending for post-market drug and vaccine safety surveillance with binomial data.

    Science.gov (United States)

    Silva, Ivair R

    2017-09-25

    Type I error probability spending functions are commonly used for designing sequential analysis of binomial data in clinical trials, but it is also quickly emerging for near-continuous sequential analysis of post-market drug and vaccine safety surveillance. It is well known that, for clinical trials, when the null hypothesis is not rejected, it is still important to minimize the sample size. Unlike in post-market drug and vaccine safety surveillance, that is not important. In post-market safety surveillance, specially when the surveillance involves identification of potential signals, the meaningful statistical performance measure to be minimized is the expected sample size when the null hypothesis is rejected. The present paper shows that, instead of the convex Type I error spending shape conventionally used in clinical trials, a concave shape is more indicated for post-market drug and vaccine safety surveillance. This is shown for both, continuous and group sequential analysis. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Fused lasso algorithm for Cox' proportional hazards and binomial logit models with application to copy number profiles.

    Science.gov (United States)

    Chaturvedi, Nimisha; de Menezes, Renée X; Goeman, Jelle J

    2014-05-01

    This paper presents an efficient algorithm based on the combination of Newton Raphson and Gradient Ascent, for using the fused lasso regression method to construct a genome-based classifier. The characteristic structure of copy number data suggests that feature selection should take genomic location into account for producing more interpretable results for genome-based classifiers. The fused lasso penalty, an extension of the lasso penalty, encourages sparsity of the coefficients and their differences by penalizing the L1-norm for both of them at the same time, thus using genomic location. The major advantage of the algorithm over other existing fused lasso optimization techniques is its ability to predict binomial as well as survival response efficiently. We apply our algorithm to two publicly available datasets in order to predict survival and binary outcomes.

  6. Correcting for binomial measurement error in predictors in regression with application to analysis of DNA methylation rates by bisulfite sequencing.

    Science.gov (United States)

    Buonaccorsi, John; Prochenka, Agnieszka; Thoresen, Magne; Ploski, Rafal

    2016-09-30

    Motivated by a genetic application, this paper addresses the problem of fitting regression models when the predictor is a proportion measured with error. While the problem of dealing with additive measurement error in fitting regression models has been extensively studied, the problem where the additive error is of a binomial nature has not been addressed. The measurement errors here are heteroscedastic for two reasons; dependence on the underlying true value and changing sampling effort over observations. While some of the previously developed methods for treating additive measurement error with heteroscedasticity can be used in this setting, other methods need modification. A new version of simulation extrapolation is developed, and we also explore a variation on the standard regression calibration method that uses a beta-binomial model based on the fact that the true value is a proportion. Although most of the methods introduced here can be used for fitting non-linear models, this paper will focus primarily on their use in fitting a linear model. While previous work has focused mainly on estimation of the coefficients, we will, with motivation from our example, also examine estimation of the variance around the regression line. In addressing these problems, we also discuss the appropriate manner in which to bootstrap for both inferences and bias assessment. The various methods are compared via simulation, and the results are illustrated using our motivating data, for which the goal is to relate the methylation rate of a blood sample to the age of the individual providing the sample. Copyright © 2016 John Wiley & Sons, Ltd.

  7. Modelling noise in second generation sequencing forensic genetics STR data using a one-inflated (zero-truncated) negative binomial model

    DEFF Research Database (Denmark)

    Vilsen, Søren B.; Tvedebrink, Torben; Mogensen, Helle Smidt;

    2015-01-01

    –10% of the total marker coverage. In comparison, our method resulted in three allelic drop-outs (true alleles below threshold), whereas the 10%-threshold induced 12 drop-outs. The non-filtered error reads (e.g. stutters, shoulders and reads with miscalled bases) will subsequently be modelled by different...

  8. QNB: differential RNA methylation analysis for count-based small-sample sequencing data with a quad-negative binomial model

    National Research Council Canada - National Science Library

    Lian Liu; Shao-Wu Zhang; Yufei Huang; Jia Meng

    2017-01-01

    Background As a newly emerged research area, RNA epigenetics has drawn increasing attention recently for the participation of RNA methylation and other modifications in a number of crucial biological processes...

  9. Describing Anopheles arabiensis aquatic habitats in two riceland agro-ecosystems in Mwea, Kenya using a negative binomial regression model with a non-homogenous mean.

    Science.gov (United States)

    Jacob, Benjamin G; Griffith, Daniel; Muturi, Ephantus; Caamano, Erick X; Shililu, Josephat; Githure, John I; Novak, Robert J

    2009-01-01

    This research illustrates a geostatistical approach for modeling the spatial distribution patterns of Anopheles arabiensis Patton (Patton) aquatic habitats in two riceland environments. QuickBird 0.61 m data, encompassing the visible bands and the near-infra-red (NIR) band, were selected to synthesize images of An. arabiensis aquatic habitats. These bands and field sampled data were used to determine ecological parameters associated with riceland larval habitat development. SAS was used to calculate univariate statistics, correlations and Poisson regression models. Global autocorrelation statistics were generated in ArcGISfrom georeferenced Anopheles aquatic habitats in the study sites. The geographic distribution of Anopheles gambiae s.l. aquatic habitats in the study sites exhibited weak positive autocorrelation; similar numbers of log-larval count habitats tend to clustered in space. Individual rice land habitat data were further evaluated in terms of their covariations with spatial autocorrelation, by regressing them on candidate spatial filter eigenvectors. Each eigenvector generated from a geographically weighted matrix, for both study sites, revealed a distinctive spatial pattern. The spatial autocorrelation components suggest the presence of roughly 14-30% redundant information in the aquatic habitat larval count samples. Synthetic map pattern variables furnish a method of capturing spatial dependency effects in the mean response term in regression analyses of rice land An. arabiensis aquatic habitat data.

  10. Negative Binomial Fits to Multiplicity Distributions from Central Collisions of (16)O+Cu at 14.6A GeV/c and Intermittency

    Science.gov (United States)

    Tannenbaum, M. J.

    1994-01-01

    The concept of "Intermittency" was introduced by Bialas and Peschanski to try to explain the "large" fluctuations of multiplicity in restricted intervals of rapidity or pseudorapidity. A formalism was proposed to to study non-statistical (more precisely, non-Poisson) fluctuations as a function of the size of rapidity interval, and it was further suggested that the "spikes" in the rapidity fluctuations were evidence of fractal or intermittent behavior, in analogy to turbulence in fluid dynamics which is characterized by self-similar fluctuations at all scales-the absence of well defined scale of length.

  11. Two Kinds of Series Involving the Reciprocals of Binomial Coefficients%两类关于二项式系数倒数的级数

    Institute of Scientific and Technical Information of China (English)

    宋海涛

    2011-01-01

    By applying the theory of formal power series, the author obtains the closed forms for two kinds of infinite series involving the reciprocals of binomial coefficients, and the author gets another closed form for the infinite series Σ r≥mtn+r/(n+rr).

  12. Some Meaningful Mathematics in Two Chapters: Chapter T1, The Binomial Expansion and Related Topics; Chapter T2, The Principle of Math Induction and Related Conjectures.

    Science.gov (United States)

    Titterton, J. Patrick

    The author presents material suitable for use by teachers of gifted students in the junior or senior year of high school. The mathematics presented includes mathematical induction, the binomial expansion, number theory and Pascal's triangle. The author weaves much of the history of mathematics into the materials. Included are student tests and…

  13. Orchestrating Semiotic Leaps from Tacit to Cultural Quantitative Reasoning--The Case of Anticipating Experimental Outcomes of a Quasi-Binomial Random Generator

    Science.gov (United States)

    Abrahamson, Dor

    2009-01-01

    This article reports on a case study from a design-based research project that investigated how students make sense of the disciplinary tools they are taught to use, and specifically, what personal, interpersonal, and material resources support this process. The probability topic of binomial distribution was selected due to robust documentation of…

  14. 青少年跨栏初学者恐惧心理初探%Primary Research on the Psychology of Fear of the Juvenile Hurdles Abecedarian

    Institute of Scientific and Technical Information of China (English)

    陈大莺

    2013-01-01

    Juvenile hurdles abecedarian usually feel fear during hurdles studying , which forming psychological bar-riers to learning the hurdles skills .Contraposed the problem , it analyses the causes of fear , from the aspect of the psychological characteristics of juvenile .And it suggests: teachers can use the methods of cultivating students 'learning motivation , making reasonable arrangement of teaching progress and teaching goa according to their own situationin to help the students to overcome the psychological barriers and put their heart into skills learning .In ad-dition, teachers should also pay attention to the cultivation of the students ’ willpower.%针对在教学过程中青少年在学习跨栏时经常出现恐惧心理,形成心理障碍以致不能学习跨栏技能的问题,本文从青少年的心理特点出发,分析青少年跨栏初学者产生恐惧心理的原因,并提出如下建议:教师可以在教学中通过培养学生学习动机、合理安排教学进度、根据学生自身状况制定教学目标等方法,让学生能够克服心理障碍,全身心的投入到技能学习中。另外,教师除了对学生进行技能培养外,还应该注意学生意志品格的培养。

  15. 栅栏技术在泡椒凤爪保藏中的应用%Application of Hurdle Technology in Pickled Chicken Feet Preservation

    Institute of Scientific and Technical Information of China (English)

    杨欢; 李思宁; 闫志农; 卢晓黎

    2012-01-01

    应用栅栏技术,对泡椒凤爪的脂肪含量、水分活度、pH值及复合防腐剂的复配比例4个栅栏因子进行了研究,以感官评分和保藏时间为指标,确定泡椒风爪保藏的最佳栅栏条件。通过四因素三水平正交试验结果得到泡椒凤爪的最佳栅栏因子组合为:脂肪含量13.2g/100mL,水分活度0.809,pH4.0,复合防腐剂(乳酸链球菌素:双乙酸钠)添加量0.1g/100mL、复配比1:3。通过验证实验可知,在此条件下,泡椒凤爪于温度37℃、相对湿度80%、光照33%条件下可贮藏50d。%Hurdle technology was used to determine optimal conditions for preserving pickled chicken feet. Fat content, water activity, pH and nisin-to-sodium diacetate ratio were identified as hurdle factors. A four-factor, three-level orthogonal array design was used to optimize these hurdle factors based on sensory score and shelf life. The optimal hurdle conditions for preserving pickled chicken feet were established as follows: fat content 13.2 g/100 mL, water activity 0.809, pH 4.0 and a mixture of nisin of sodium diacetate at a ratio of 1:3 as a preservative. Under these conditions, the shelf life of pickled chicken feet in an environment of 37 ℃, 80% humidity and 33% light exposure was 50 day.

  16. Modeling Zero-Inflated and Overdispersed Count Data: An Empirical Study of School Suspensions

    Science.gov (United States)

    Desjardins, Christopher David

    2016-01-01

    The purpose of this article is to develop a statistical model that best explains variability in the number of school days suspended. Number of school days suspended is a count variable that may be zero-inflated and overdispersed relative to a Poisson model. Four models were examined: Poisson, negative binomial, Poisson hurdle, and negative…

  17. Effects of sonication and ultraviolet-C treatment as a hurdle concept on quality attributes of Chokanan mango (Mangifera indica L.) juice.

    Science.gov (United States)

    Santhirasegaram, Vicknesha; Razali, Zuliana; Somasundram, Chandran

    2015-04-01

    The growing demand for fresh-like food products has encouraged the development of hurdle technology of non-thermal processing. In this study, freshly squeezed Chokanan mango juice was treated by paired combinations of sonication (for 15 and 30 min at 25 ℃, 40 kHz frequency) and UV-C treatment (for 15 and 30 min at 25 ℃). Selected physicochemical properties, antioxidant activities, microbial inactivation and other quality parameters of combined treated juice were compared to conventional thermal treatment (at 90 ℃ for 60 s). After thermal and combined treatment, no significant changes occurred in physicochemical properties. A significant increase in extractability of carotenoids (15%), polyphenols (37%), flavonoids (35%) and enhancement in antioxidant capacity was observed after combined treatment. Thermal and combined treatment exhibited significant reduction in microbial load. Results obtained support the use of sonication and UV-C in a hurdle technology to improve the quality of Chokanan mango juice along with safety standards. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  18. The Application of Hurdle Technology in Bibliographic Data 's Checking%栅栏技术在书目数据审校中的应用

    Institute of Scientific and Technical Information of China (English)

    武英杰

    2016-01-01

    In order to ensure the accuracy and standardization of bibliographic data,the bibliographic data production units should check and review the compiled bibliographies by the proofreaders, so, the professional ability of the proofreaders plays a decisive role in improving the quality of bibliographic data. This paper expounds the application of hurdle technology in bibliographic data's checking, that is to look for the hurdle factors of bibliographic data, and fulfill the bibliographic data checking by using the interaction among these factors to ultimately achieve the goal of improving the data quality.%为了确保书目数据的准确性和规范性, 书目数据制作单位都要由审校人员对已编书目进行核对、 审查, 因此审校员的业务能力对提高书目数据质量起着决定性的作用. 阐述了栅栏技术在书目数据审校中的应用, 即通过寻找书目数据的栅栏因子,利用这些因子间的相互作用,来完成书目数据的审校工作,最终达到提高数据质量的目的.

  19. Feasibility analysis in the expansion proposal of the nuclear power plant Laguna Verde: application of real options, binomial model; Analisis de viabilidad en la propuesta de expansion de la central nucleoelectrica Laguna Verde: aplicacion de opciones reales, modelo binomial

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez I, S.; Ortiz C, E.; Chavez M, C., E-mail: lunitza@gmail.com [UNAM, Facultad de Ingenieria, Circuito Interior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2011-11-15

    At the present time, is an unquestionable fact that the nuclear electrical energy is a topic of vital importance, no more because eliminates the dependence of the hydrocarbons and is friendly with the environment, but because is also a sure and reliable energy source, and represents a viable alternative before the claims in the growing demand of electricity in Mexico. Before this panorama, was intended several scenarios to elevate the capacity of electric generation of nuclear origin with a variable participation. One of the contemplated scenarios is represented by the expansion project of the nuclear power plant Laguna Verde through the addition of a third reactor that serves as detonator of an integral program that proposes the installation of more nuclear reactors in the country. Before this possible scenario, the Federal Commission of Electricity like responsible organism of supplying energy to the population should have tools that offer it the flexibility to be adapted to the possible changes that will be presented along the project and also gives a value to the risk to future. The methodology denominated Real Options, Binomial model was proposed as an evaluation tool that allows to quantify the value of the expansion proposal, demonstrating the feasibility of the project through a periodic visualization of their evolution, all with the objective of supplying a financial analysis that serves as base and justification before the evident apogee of the nuclear energy that will be presented in future years. (Author)

  20. 世界优秀女子100 m跨栏跑运动员技术特征分析%Analysis of the Women's 100 m Hurdles World Excellent Athletes Run Technical Characteristic

    Institute of Scientific and Technical Information of China (English)

    吕艳丽; 胡洪泉

    2015-01-01

    为了进一步认识100 m跨栏跑技术特征,该文分析统计第六届、第十二届世锦赛共14名100 m跨栏跑运动员决赛成绩的相关参数,研究结果表明:(1)100 m跨栏跑在不同栏位耗时具有共同规律,即第一、二个跨栏周期耗时稍长一点,第三、四、五、六跨栏周期耗时逐渐趋于稳定,第七、八、九跨栏周期耗时逐渐延长;(2)世界优秀100 m跨栏跑运动员在起跑反应时、最大速度出现的时间、起跑至第1栏的耗时相差较小,且与成绩相关性较弱;(3)跨栏周期最大速度、9个跨栏周期耗时、跨栏周期耗时低于1s个数、9个跨栏周期的平均速度与100 m跨栏跑成绩存在线性关系;(4)第二、三区域耗时是决定100 m跨栏跑成绩的关键区域,该区域耗时直接反应运动员最大速度、保持最大速度以及冲刺速度能力。%In order to further understand the 100m hurdles technical features, this paper analyzes statistics sixth, twelfth World Championship a total of 14 athletes,100m hurdles final performance parameters, the results show that:(1) 100m hurdle in different fields time-consuming has obvious common law, namely the first,the two hurdle cycle takes a little longer, third, four or five, six hurdle cycle time consuming gradually stabilized,seventh,the eight or nine hurdle cycle time gradually increased; (2) the world's best athletes in the 100m hurdles start reaction,the maximum speed occurs, starting in column 1 to a smaller difference between the time-consuming aspects,and weak correlation with the results;(3)the maximum cycle speed hurdles, 9 cycle time-consuming hurdles,hurdles cycle is lower than the number of 1s,nine cycles, the average speed of hurdles 100m hurdles results with a linear relationship;(4) the second and third regional consumption 100m hurdles is to determine when a key performance area, the area took a direct response to player maximum speed,maximum speed and sprint speed

  1. Binomial probability distribution model-based protein identification algorithm for tandem mass spectrometry utilizing peak intensity information.

    Science.gov (United States)

    Xiao, Chuan-Le; Chen, Xiao-Zhou; Du, Yang-Li; Sun, Xuesong; Zhang, Gong; He, Qing-Yu

    2013-01-04

    Mass spectrometry has become one of the most important technologies in proteomic analysis. Tandem mass spectrometry (LC-MS/MS) is a major tool for the analysis of peptide mixtures from protein samples. The key step of MS data processing is the identification of peptides from experimental spectra by searching public sequence databases. Although a number of algorithms to identify peptides from MS/MS data have been already proposed, e.g. Sequest, OMSSA, X!Tandem, Mascot, etc., they are mainly based on statistical models considering only peak-matches between experimental and theoretical spectra, but not peak intensity information. Moreover, different algorithms gave different results from the same MS data, implying their probable incompleteness and questionable reproducibility. We developed a novel peptide identification algorithm, ProVerB, based on a binomial probability distribution model of protein tandem mass spectrometry combined with a new scoring function, making full use of peak intensity information and, thus, enhancing the ability of identification. Compared with Mascot, Sequest, and SQID, ProVerB identified significantly more peptides from LC-MS/MS data sets than the current algorithms at 1% False Discovery Rate (FDR) and provided more confident peptide identifications. ProVerB is also compatible with various platforms and experimental data sets, showing its robustness and versatility. The open-source program ProVerB is available at http://bioinformatics.jnu.edu.cn/software/proverb/ .

  2. Asimetría y curtosis en el modelo binomial para valorar opciones reales: caso de aplicación para empresas de base tecnológica

    Directory of Open Access Journals (Sweden)

    Gastón Silverio Milanesi

    2013-01-01

    Full Text Available El trabajo propone un modelo de valoración de opciones reales con base en el modelo binomial utilizando la transformación de Edgeworth (Rubinstein, 1998 para incorporar momentos estocásticos de orden superior, especialmente para ciertos tipos de organizaciones, como empresas de base tecnológica, donde no se dispone de cartera de activos financieros gemelos, comparables de mercado y procesos estocásticos no gaussianos. Primero, se presenta el desarrollo formal del modelo, luego su aplicación sobre la valuación de spin-off tecnológico universitario, sensibilizando asimetría-curtosis y exponiendo el impacto en el valor del proyecto. Finalmente, se concluye sobre limitaciones y ventajas de la propuesta de valoración que resume la simplicidad del modelo binomial e incorporando momentos de orden superior en subyacentes con procesos no normales.

  3. Asimetría y curtosis en el modelo binomial para valorar opciones reales: caso de aplicación para empresas de base tecnológica

    Directory of Open Access Journals (Sweden)

    Gastón Silverio Milanesi

    2013-07-01

    Full Text Available El trabajo propone un modelo de valoración de opciones reales con base en el modelo binomial utilizando la transformación de Edgeworth (Rubinstein, 1998 para incorporar momentos estocásticos de orden supe- rior, especialmente para ciertos tipos de organizaciones, como empresas de base tecnológica, donde no se dispone de cartera de activos financieros gemelos, comparables de mercado y procesos estocásticos no gaussianos. Primero, se presenta el desarrollo formal del modelo, luego su aplicación sobre la valuación de spin-off tecnológico universitario, sensibilizando asimetría-curtosis y exponiendo el impacto en el valor del proyecto. Finalmente, se concluye sobre limitaciones y ventajas de la propuesta de valoración que resume la simplicidad del modelo binomial e incorporando momentos de orden superior en subyacentes con pro- cesos no normales.

  4. 二项分布参数的p-值检验%The p-Value Testing of the Parameter of Binomial Distribution

    Institute of Scientific and Technical Information of China (English)

    吕佳; 任芳玲; 赵子墨

    2015-01-01

    Firstly,the regularized incomplete Beta function was used to reveal the relationship between binomial distribution and beta distribution. The related conclusion can be used to get the test statistic. Further ,we derivated the method and the formula for computing the p-value in the test about the parameter of binomial distribution. Lastly, an example was given to show the application of the method.%首先利用正则不完全贝塔函数揭示二项分布与贝塔分布的关系,并利用相关结论获得了检验统计量。进一步给出二项分布参数的单侧显著性检验p-值的计算方法和计算公式。最后,结合实例对所给方法进行了演示。

  5. The Survival Probability in Generalized Compund Binomial Risk Model%广义复合二项风险模型下的生存概率

    Institute of Scientific and Technical Information of China (English)

    龚日朝; 刘永清

    2001-01-01

    将复合二项风险模型的保费收入过程由单位时间内收取定常数推广为一个Poisson过程,即在单位时间内收取的保单数服从强度为的Poisson分布,假定每张保单的保费均为常数.然后研究了当赔付服从参数为的指数分布时,有限时间内的生存概率.%In this paper we considered a generalized compound binomial risk model, which the occurrence of the premium is described by a Poisson process. Then we got the survival probability in finite time period of an insurance company having initial capital in the generalized compound binomial risk model, when the individual claim size distribution is exponential with a parameter.

  6. Negation and negative concord in romance

    NARCIS (Netherlands)

    Swart, Henriëtte de; Sag, I.A.

    This paper addresses the two interpretations a combination of negative indefinites can get in concord languages like French, namely a concord reading which amounts to a single negation, or a double negation reading. We develop an analysis in a polyadic framework, in which a sequence of

  7. Breeding biology of muscovy duck (Cairina moschata) under natural incubation: the use of the weibull function and a beta-binomial model to predict nest hatchability

    Science.gov (United States)

    Harun; Draisma; Frankena; Veeneklaas; Van Kampen M

    1999-05-07

    In this paper we tested the Weibull function and beta-binomial distribution to analyse and predict nest hatchability, using empirical data on hatchability in Muscovy duck (Cairina moschata) eggs under natural incubation (932 successfully incubated nests and 11 822 eggs). The estimated parameters of the Weibull function and beta-binomial model were compared with the logistic regression analysis. The maximum likelihood estimation of the parameters was used to quantify simultaneously the influence of the nesting behaviour and the duration of the reproduction cycle on hatchability. The estimated parameters showed that the hatchability was not affected in natural dump nests, but in artificial dump nests and in nests with non-term eggs the hatchability was reduced by 10 and 25%, respectively. Similar results were obtained using logistic regression. Both models provided a satisfactory description of the observed data set, but the beta-binomial model proved to have more parameters with practical and biological meaningful interpretations, because this model is able to quantify and incorporate the unexplained variation in a single parameter theta (which is a variance measure). Copyright 1999 Academic Press.

  8. Stability of mango cubes preserved by hurdle technology Estabilidade de cubos de manga conservados pela tecnologia de obstáculos

    Directory of Open Access Journals (Sweden)

    Henriette Monteiro Cordeiro de Azeredo

    2005-04-01

    Full Text Available Fruit preservation by hurdle technology is based on combinations of low levels of various antimicrobial factors (hurdles acting synergistically resulting in a shelf stable high moisture, fresh-like product. The objective of this work was to evaluate the stability of mango cubes obtained by combining the following hurdles: water activity reduction, pH reduction, and chemical preservation. Tommy Atkins mangoes, previously washed, sanitized and peeled, were cut into cubes of approximately 8 cm³. The cubes were osmotically dehydrated under stirring (150 rpm at 46ºC in a sucrose solution at 65.5oBrix added with 2% citric acid and 0.2% potassium sorbate, during two hours. The product was drained, packed in low-density polyethylene bags and stored at room temperature (about 25ºC during three months. The combination of hurdles on the final product (water activity, 0.96; pH, 3.99; potassium sorbate content, 396 mg.kg-1 was not effective to make it shelf stable, since the count of yeasts and molds increased. The cubes underwent pH reduction and color losses during storage. Furthermore, the acceptance of the product, as well as, the mango flavor intensity, decrease significantly with storage time.A conservação pela tecnologia de obstáculos baseia-se na combinação de vários fatores antimicrobianos (obstáculos, todos aplicados em baixos níveis, atuando sinergicamente e resultando em um produto de alta umidade, semelhante ao correspondente fresco, e com boa estabilidade à temperatura ambiente. Conduziu-se este trabalho com o objetivo de avaliar a estabilidade de cubos de manga conservados pela combinação dos seguintes obstáculos: redução da atividade de água, redução do pH e conservação química. Mangas Tommy Atkins, previamente lavadas, sanitizadas e descascadas, foram cortadas em cubos de aproximadamente 8 cm³. Os cubos foram desidratados osmoticamente, sob agitação (150 rpm, a 46ºC em uma solução de sacarose a 65,5º

  9. Confidence intervals for the difference between independent binomial proportions: comparison using a graphical approach and moving averages.

    Science.gov (United States)

    Laud, Peter J; Dane, Aaron

    2014-01-01

    This paper uses graphical methods to illustrate and compare the coverage properties of a number of methods for calculating confidence intervals for the difference between two independent binomial proportions. We investigate both small-sample and large-sample properties of both two-sided and one-sided coverage, with an emphasis on asymptotic methods. In terms of aligning the smoothed coverage probability surface with the nominal confidence level, we find that the score-based methods on the whole have the best two-sided coverage, although they have slight deficiencies for confidence levels of 90% or lower. For an easily taught, hand-calculated method, the Brown-Li 'Jeffreys' method appears to perform reasonably well, and in most situations, it has better one-sided coverage than the widely recommended alternatives. In general, we find that the one-sided properties of many of the available methods are surprisingly poor. In fact, almost none of the existing asymptotic methods achieve equal coverage on both sides of the interval, even with large sample sizes, and consequently if used as a non-inferiority test, the type I error rate (which is equal to the one-sided non-coverage probability) can be inflated. The only exception is the Gart-Nam 'skewness-corrected' method, which we express using modified notation in order to include a bias correction for improved small-sample performance, and an optional continuity correction for those seeking more conservative coverage. Using a weighted average of two complementary methods, we also define a new hybrid method that almost matches the performance of the Gart-Nam interval.

  10. [The binomial symptom index for the evaluation of temporal association between cardiorespiratory symptoms and gastroesophageal reflux in neonates].

    Science.gov (United States)

    Barriga-Rivera, Alejandro; Moya, María José; Lopez-Alonso, Manuel

    2016-11-01

    The evaluation of symptom association between gastroesophageal reflux and cardiorespiratory events in preterm infants remains unclear. This paper describes a conservative approach to decision-making of anti-reflux surgery through symptom association analysis. Forty-three neonates with potentially reflux-related cardiorespiratory symptoms underwent synchronized esophageal impedance-pH and cardiorespiratory monitoring. Three indices were considered to evaluate symptom association, the symptom index (SI), the symptom sensitivity index (SSI) and the symptom association probability (SAP). A conservative strategy was adopted regarding the decision of anti-reflux surgery, and therefore, patients were scheduled for laparoscopic Nissen fundoplication if the three indices showed a positive assessment of symptom association. Retrospectively, these indices and the binomial symptom index (BSI) were contrasted against the decision of anti-reflux surgery using different windows of association. Thirteen patients showed positive symptom association but only two underwent anti-reflux surgery. The SI and the SSI showed an increasing trend with the width of the window of association. The SAP was affected randomly by slightly altering the windowing parameters. The BSI showed the best performance with the two-minute window (κ =0.78) CONCLUSIONS: The pathology under study is known to improve with maturity. However, the severity of cardiorespiratory symptoms may threaten the neonate's life and therefore, in some occasions, invasive treatments must be considered to protect life. The BSI provides a good prediction of a combination of positive SI, SSI and SAP, which may improve clinical decisions. However, further clinical studies are required to prove the BSI as an optimal predictor of clinical outcomes. Copyright © 2015 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  11. On the Estimation of Confidence Intervals for Binomial Population Proportions in Astronomy: The Simplicity and Superiority of the Bayesian Approach (with Recipes for Use in R, Matlab, Mathematica, and IDL)

    CERN Document Server

    Cameron, Ewan

    2010-01-01

    We present a critical review of popular techniques for estimating confidence intervals on binomial population proportions inferred from success counts in small-to-intermediate samples. Population proportions arise frequently as quantities of interest in astronomical research; most notably in studies of the fractions of galaxies exhibiting distinct structural components (stellar bars, supermassive blackholes, AGN, etc.), populating the ('quiescent') red sequence, or undergoing major/minor mergers. However, the two most widely-used techniques for estimating binomial confidence intervals - the 'normal approximation' and the Clopper & Pearson approach - perform poorly under sampling regimes routinely encountered in astronomical datasets. Hence, we provide here an overview of the fundamentals of binomial statistics with two principal aims: (i) to reveal the ease with which binomial confidence intervals with more satisfactory behaviour may be estimated from the quantiles of the beta distribution using modern ma...

  12. On Multiplying Negative Numbers.

    Science.gov (United States)

    Crowley, Mary L.; Dunn, Kenneth A.

    1985-01-01

    Comments on the history of negative numbers, some methods that can be used to introduce the multiplication of negative numbers to students, and an explanation of why the product of two negative numbers is a positive number are included. (MNS)

  13. Using a Simple Binomial Model to Assess Improvement in Predictive Capability: Sequential Bayesian Inference, Hypothesis Testing, and Power Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sigeti, David E. [Los Alamos National Laboratory; Pelak, Robert A. [Los Alamos National Laboratory

    2012-09-11

    We present a Bayesian statistical methodology for identifying improvement in predictive simulations, including an analysis of the number of (presumably expensive) simulations that will need to be made in order to establish with a given level of confidence that an improvement has been observed. Our analysis assumes the ability to predict (or postdict) the same experiments with legacy and new simulation codes and uses a simple binomial model for the probability, {theta}, that, in an experiment chosen at random, the new code will provide a better prediction than the old. This model makes it possible to do statistical analysis with an absolute minimum of assumptions about the statistics of the quantities involved, at the price of discarding some potentially important information in the data. In particular, the analysis depends only on whether or not the new code predicts better than the old in any given experiment, and not on the magnitude of the improvement. We show how the posterior distribution for {theta} may be used, in a kind of Bayesian hypothesis testing, both to decide if an improvement has been observed and to quantify our confidence in that decision. We quantify the predictive probability that should be assigned, prior to taking any data, to the possibility of achieving a given level of confidence, as a function of sample size. We show how this predictive probability depends on the true value of {theta} and, in particular, how there will always be a region around {theta} = 1/2 where it is highly improbable that we will be able to identify an improvement in predictive capability, although the width of this region will shrink to zero as the sample size goes to infinity. We show how the posterior standard deviation may be used, as a kind of 'plan B metric' in the case that the analysis shows that {theta} is close to 1/2 and argue that such a plan B should generally be part of hypothesis testing. All the analysis presented in the paper is done with a

  14. Modeling probability of additional cases of natalizumab-associated JCV sero-negative progressive multifocal leukoencephalopathy.

    Science.gov (United States)

    Carruthers, Robert L; Chitnis, Tanuja; Healy, Brian C

    2014-05-01

    JCV serologic status is used to determine PML risk in natalizumab-treated patients. Given two cases of natalizumab-associated PML in JCV sero-negative patients and two publications that question the false negative rate of the JCV serologic test, clinicians may question whether our understanding of PML risk is adequate. Given that there is no gold standard for diagnosing previous JCV exposure, the test characteristics of the JCV serologic test are unknowable. We propose a model of PML risk in JCV sero-negative natalizumab patients. Using the numbers of JCV sero-positive and -negative patients from a study of PML risk by JCV serologic status (sero-positive: 13,950 and sero-negative: 11,414), we apply a range of sensitivities and specificities in order calculate the number of JCV-exposed but JCV sero-negative patients (false negatives). We then apply a range of rates of developing PML in sero-negative patients to calculate the expected number of PML cases. By using the binomial function, we calculate the probability of a given number of JCV sero-negative PML cases. With this model, one has a means to establish a threshold number of JCV sero-negative natalizumab-associated PML cases at which it is improbable that our understanding of PML risk in JCV sero-negative patients is adequate.

  15. 二项分布参数p置信区间评估算法分析%Analysis of a Binomial Parameter p Confidence Interval Evaluation Algorithm

    Institute of Scientific and Technical Information of China (English)

    刘镇瑜; 王军; 王凌艳; 林秋杰; 霍烁烁

    2013-01-01

    Binomial distribution was frequently encountered in various tests. There were many parameter evaluation methods,but the performances were not ideal even in engineering standards. According to discrete characteristics of the binomial distribution,we sug-gested a confidence interval evaluation brute algorithm of binomial distribution parameter p. The algorithm traversed p with fine step,and corrected every confidence interval to adapt to the level of significance. When it traversed all parameters,the confidence interval could be obtained. Three evaluation indicators of confidence interval were provided. Compared with other methods,this algorithm was correct and effective.%二项分布是各种试验中经常遇到的一种分布类型,当前有很多参数评估方法,但是包括工程标准在内的很多方法性能并不是很优。根据二项分布离散性的特点提出了一种二项分布参数 p置信区间评估的暴力算法。算法对二项分布参数 p进行精细步长的遍历,在每一个参数值点根据置信水平对置信区间进行修正,遍历完所有的参数即可得到所需的置信区间。给出置信区间的3项评价指标,通过和其他置信区间评估方法的对比分析可知,算法正确、有效。

  16. Tipificación de los errores que se presentan al identificar una variable aleatoria de distribución binomial en problemas contextualizados

    OpenAIRE

    Vilca Alvarez, Marhori

    2015-01-01

    La distribución binomial es una de las más importantes distribuciones discretas. Esta distribución es usada en la medicina, la industria y en la toma de decisiones gerenciales, así como en la bolsa de valores; precisamente, en aquellas situaciones donde los posibles resultados son aleatorios y dicotómicos. Además, se estudia en las áreas de Matemática, Ingenierías y Ciencias Sociales. Tesis

  17. CONVERGENCE OF AN IMMERSED INTERFACE UPWIND SCHEME FOR LINEAR ADVECTION EQUATIONS WITH PIECEWISE CONSTANT COEFFICIENTS Ⅱ: SOME RELATED BINOMIAL COEFFICIENT INEQUALITIES

    Institute of Scientific and Technical Information of China (English)

    Xin Wen

    2009-01-01

    In this paper we give proof of three binomial coefficient inequalities. These inequalities are key ingredients in [Wen and Jin, J. Comput. Math. 26, (2008), 1-22] to establish the L1-error estimates for the upwind difference scheme to the linear advection equations with a piecewise constant wave speed and a general interface condition, which were further used to establish the L1-error estimates for a Hamiltonian-preserving scheme developed in [Jin and Wen, Commun. Math. Sci. 3, (2005), 285-315] to the Liouville equation with piecewise constant potentials [Wen and Jin, SIAM J. Numer. Anal. 46, (2008), 2688-2714].

  18. Negating the Verum

    DEFF Research Database (Denmark)

    Ørsnes, Bjarne

    2012-01-01

    In Danish the base position of the negation (and negated quantifier phrases) is between the subject and the finite verb in embedded clauses. However, in embedded clauses introduced by a non-veridical complementizer such as hvis ‘if’ or om ‘whether’, the negation can also appear between the comple......In Danish the base position of the negation (and negated quantifier phrases) is between the subject and the finite verb in embedded clauses. However, in embedded clauses introduced by a non-veridical complementizer such as hvis ‘if’ or om ‘whether’, the negation can also appear between...

  19. Negation in English

    Institute of Scientific and Technical Information of China (English)

    宋炳

    2016-01-01

    Every language has its own unique ways of negation and English is no exception. More importance should be attached to when a negative English sentence is translated into its Chinese equivalent. Negation in English can be realized in many differ-ent ways. In the first place, the different types of negation in English will be analyzed. In addition, the affixes and lexicons used to denote negation will be investigated. The last part is mainly concerning the idioms and other expressions which denote nega-tive meanings. In order to make the views much more clearly, some Chinese equivalents of the English sentences will be offered here.

  20. 栅栏技术在麻糬生产综合防腐中的应用%Application of Hurdle Technology on the Synthetic Preservation of Mochi

    Institute of Scientific and Technical Information of China (English)

    吴浩; 邵华平; 朱勇; 王隽; 吴志恒; 张煜炯

    2012-01-01

    根据栅栏技术因子保鲜理论,采用多种栅栏因子的科学组合,对麻糬生产进行综合防腐的研究.结果表明:产品水分活度0.83+防腐配方(山梨酸钾0.6 mg/kg、脱氢乙酸钠0.2mg/kg)+芝麻处理(0.02MPa蒸汽蒸30 min、150℃烘烤45 min)+紫外线杀菌处理(4W/m2,35 min),产品能在常温下(15~20℃)保存60d不变质、不长霉.%The results indicated that the treated product would be kept at a range of room temperature (15-20℃) for 60 days without degeneration and mildew when the following hurdle factors forraw material sesame were adopted (pressure 02 Mpa, vapor-treatment time 30 minutes, roast temperature 150℃,roast time 45 minutes, water activity 0.83, potassium sorbate 0.6 mg/kg,sodium dehydroacetate 0.2 mg/kg and UV sterilization time 35 minute at 4 W/m2).

  1. Investigations on non-inferiority--the Food and Drug Administration draft guidance on treatments for nosocomial pneumonia as a case for exact tests for binomial proportions.

    Science.gov (United States)

    Röhmel, Joachim; Kieser, Meinhard

    2013-06-30

    This paper addresses statistical issues in non-inferiority trials where the primary outcome is a fatal event. The investigations are inspired by a recent Food and Drug Administration (FDA) draft guideline on treatments for nosocomial pneumonia. The non-inferiority margin suggested in this guideline for the endpoint all-cause mortality is defined on different distance measures (rate difference and odds ratio) and is discontinuous. Furthermore, the margin enables considerable power for the statistical proof of non-inferiority at alternatives that might be regarded as clinically unacceptable, that is, even if the experimental treatment is harmful as compared with the control. We investigated the appropriateness of the proposed non-inferiority margin as well as the performance of possible test statistics to be used for the analysis. A continuous variant of the margin proposed in the FDA guideline together with the unconditional exact test according to Barnard showed favorable characteristics with respect to type I error rate control and power. To prevent harmful new treatments from being declared as non-inferior, we propose to add a 'second hurdle'. We discuss examples and explore power characteristics when requiring both statistical significance and overcoming the second hurdle.

  2. Sentential Negation in English

    Science.gov (United States)

    Mowarin, Macaulay

    2009-01-01

    This paper undertakes a detailed analysis of sentential negation in the English language with Chomsky's Government-Binding theory of Transformational Grammar as theoretical model. It distinguishes between constituent and sentential negation in English. The essay identifies the exact position of Negation phrase in an English clause structure. It…

  3. Sentential Negation in English

    Science.gov (United States)

    Mowarin, Macaulay

    2009-01-01

    This paper undertakes a detailed analysis of sentential negation in the English language with Chomsky's Government-Binding theory of Transformational Grammar as theoretical model. It distinguishes between constituent and sentential negation in English. The essay identifies the exact position of Negation phrase in an English clause structure. It…

  4. A New Extension of the Binomial Error Model for Responses to Items of Varying Difficulty in Educational Testing and Attitude Surveys.

    Directory of Open Access Journals (Sweden)

    James A Wiley

    Full Text Available We put forward a new item response model which is an extension of the binomial error model first introduced by Keats and Lord. Like the binomial error model, the basic latent variable can be interpreted as a probability of responding in a certain way to an arbitrarily specified item. For a set of dichotomous items, this model gives predictions that are similar to other single parameter IRT models (such as the Rasch model but has certain advantages in more complex cases. The first is that in specifying a flexible two-parameter Beta distribution for the latent variable, it is easy to formulate models for randomized experiments in which there is no reason to believe that either the latent variable or its distribution vary over randomly composed experimental groups. Second, the elementary response function is such that extensions to more complex cases (e.g., polychotomous responses, unfolding scales are straightforward. Third, the probability metric of the latent trait allows tractable extensions to cover a wide variety of stochastic response processes.

  5. A New Extension of the Binomial Error Model for Responses to Items of Varying Difficulty in Educational Testing and Attitude Surveys.

    Science.gov (United States)

    Wiley, James A; Martin, John Levi; Herschkorn, Stephen J; Bond, Jason

    2015-01-01

    We put forward a new item response model which is an extension of the binomial error model first introduced by Keats and Lord. Like the binomial error model, the basic latent variable can be interpreted as a probability of responding in a certain way to an arbitrarily specified item. For a set of dichotomous items, this model gives predictions that are similar to other single parameter IRT models (such as the Rasch model) but has certain advantages in more complex cases. The first is that in specifying a flexible two-parameter Beta distribution for the latent variable, it is easy to formulate models for randomized experiments in which there is no reason to believe that either the latent variable or its distribution vary over randomly composed experimental groups. Second, the elementary response function is such that extensions to more complex cases (e.g., polychotomous responses, unfolding scales) are straightforward. Third, the probability metric of the latent trait allows tractable extensions to cover a wide variety of stochastic response processes.

  6. A Study of Application of Wheel Running in the 110m Hurdle Auxiliary Exercises%车轮跑在110m栏辅助练习中的运用研究

    Institute of Scientific and Technical Information of China (English)

    杨君; 李华; 梁慧

    2012-01-01

    According to the technology comparation in wheel-running practice and 110m hurdles race,which have a lot of similarities in the extreme nature,explosive force and the hip-axis high-speed swing,it is recommended that we could include the wheels running into in the auxiliary exercise of 110m hurdles race,and should always throughout training.%根据车轮跑练习与110m跨栏跑的技术比较,两者在极限性、爆发性发力以及髋关节为轴的高速摆动都有很大的相似性,建议把车轮跑划入110m跨栏跑的辅助性练习中,并应贯穿于整个训练的始终。

  7. Counterland Doctrine - An Integration Hurdle

    Science.gov (United States)

    2006-05-31

    support (CAS). Recent historical analysis shows that although AI and CAS missions have been effective on the battlefield, AI and CAS do not fully describe...support (CAS). Recent historical analysis shows that although AI and CAS missions have been effective on the battlefield, AI and CAS do not fully...plan for eventual NATO advance. Follow- On Forces Attack ( FOFA ) doctrine relied heavily on the Strategic Air Command (SAC) and was viewed by many in

  8. 大学生学习跨栏跑克服心理障碍的研究%Research on How to Overcome the Psychological Barriers of Students' Hurdle Learning in University

    Institute of Scientific and Technical Information of China (English)

    邵丽霞

    2014-01-01

    跨栏跑是大学生田径必修课的教学内容之一,跨栏跑可以发展学生的速度、弹跳、灵敏、柔韧等综合素质。采用文献资料法、问卷调查法、实验法析法对学生跨栏跑产生心理障碍的原因进行详细分析,并针对这些原因提出相应的对策研究。同时被调查的学生通过心理辅导消除了心理障碍并在跨栏技术上得到了很大的提升。%Hurdle running is one of the teaching content of track and field compulsory class. The hurdles can develop stu-dents' speed, springing, agility, flexibility, and comprehensive quality. Therefore, this paper adopts literature, questionnaire survey, experiment to analysis reasons of psychological barrier in students' hurdles, and in the light of these reasons it puts forward the corresponding countermeasures.

  9. Envelope control of outer membrane vesicle production in Gram-negative bacteria.

    Science.gov (United States)

    Schwechheimer, Carmen; Sullivan, Claretta J; Kuehn, Meta J

    2013-05-07

    All Gram-negative bacteria studied to date have been shown to produce outer membrane vesicles (OMVs), which are budded, released spheres of outer membrane with periplasmic content. OMVs have been implicated in the delivery of virulence factors in pathogenesis. However, OMVs also benefit nonpathogenic species by delivering degradative enzymes to defend an ecological niche against competing bacterial species, and they can serve as an envelope stress response. Despite these important roles, very little is known about the mechanism of production of OMVs. Here we review the advantage of vesiculation, particularly in a nonpathogenic context, as well as the hurdles that have to be overcome in Gram-negative envelope architecture before a vesicle can form and bud. Lastly, we address the question of whether OMV production is a stochastic or regulated process.

  10. The Analysis of Negative

    Institute of Scientific and Technical Information of China (English)

    辛琨

    2009-01-01

    @@ Chapter 1 The Meaning of Negation Negation,in our daily life,is very commonly used.When you deny something,you use it;when you refuse something,you use it too.And the most common negatiom"no"and"not"are used by US every day.

  11. Modelo binomial para la valoración de empresas y los efectos de la deuda: escudo fiscal y liquidación de la firma

    Directory of Open Access Journals (Sweden)

    Gastón Silverio Milanesi

    2014-06-01

    Full Text Available En este documento se propone un modelo binomial para valorar empresas, proyectando y condicionando escenarios de continuidad o liquidación de la firma. El modelo se basa en la Teoría de Opciones Reales para estimar el valor de la firma, que resulta de un balance explícito de las ventajas y riesgos de tomar deuda. El trabajo se estructura de la siguiente manera: Primeramente, la introducción y desarrollo del modelo teórico; luego se ilustra mediante un caso de aplicación, comparando los resultados obtenidos con el modelo de descuento de flujos de fondos. Se sensibilizan variables como: endeudamiento, tasa de impuesto y volatilidad para analizar el impacto en el valor de la empresa. Finalmente, se describen las ventajas del modelo propuesto.

  12. 二项分布可靠度E-Bayes估计的性质%Properties of E-Bayesian Estimation for the Reliability Derived form Binomial Distribution

    Institute of Scientific and Technical Information of China (English)

    韩明

    2013-01-01

    作者以前提出了一种新的参数估计方法——E-Bayes估计法,对二项分布的可靠度,给出了E-Bayes估计的定义、E-Bayes估计和多层Bayes估计公式,但没有给出E-Bayes估计的性质.该文给出了二项分布可靠度F-Bayes估计的性质.%Previously, the author introduces a new parameter estimation method-E-Bayesian estimation method, to estimate the reliability derived form Binomial distribution, the definition of E-Bayesian estimation of the reliability is provided; moreover, formulas of E-Bayesian estimation and hierarchical Bayesian estimation for the reliability are also provided, but the author did not provide propertiy of E-Bayesian estimation. This paper, properties of E-Bayesian estimation are provided.

  13. Diagnosis of congenital Trypanosoma cruzi infection: A serologic test using Shed Acute Phase Antigen (SAPA) in mother-child binomial samples.

    Science.gov (United States)

    Volta, Bibiana J; Russomando, Graciela; Bustos, Patricia L; Scollo, Karenina; De Rissio, Ana M; Sánchez, Zunilda; Cardoni, Rita L; Bua, Jacqueline

    2015-07-01

    Chagas congenital infection is an important health problem in endemic and non-endemic areas in which Trypanosoma cruzi-infected women can transmit the parasite to their offspring. In this study, we evaluated the antibody levels against the T. cruzi Shed Acute Phase Antigen (SAPA) in 91 binomial samples of seropositive pregnant women and their infected and non-infected children by ELISA. In 70 children without congenital T. cruzi transmission, the titers of anti-SAPA antibodies were lower than those of their seropositive mothers. In contrast, 90.5% of 21 congenitally infected children, at around 1 month of age, showed higher anti-SAPA antibody levels than their mothers. Subtracting the SAPA-ELISA mother OD value to the SAPA-ELISA child OD allowed efficient detection of most T. cruzi congenitally infected children immediately after birth, when total anti-parasite antibodies transferred during pregnancy are still present in all children born to seropositive women. A positive correlation was observed between parasitemia levels in mothers and infants evaluated by quantitative DNA amplification and anti-SAPA antibody titers by ELISA. As SAPA serology has proved to be very efficient to detect T. cruzi infection in mother-child binomial samples, it could be of extreme help for early diagnosis of newborns, in maternities and hospitals where DNA amplification is not available. This prompt diagnosis may prevent drop out of the long-term follow-up for future diagnosis and may ensure early trypanocidal treatment, which has proved to be efficient to cure infants with congenital Chagas disease.

  14. MultiTest V.1.2, a program to binomially combine independent tests and performance comparison with other related methods on proportional data

    Directory of Open Access Journals (Sweden)

    Guégan Jean-François

    2009-12-01

    Full Text Available Abstract Background Combining multiple independent tests, when all test the same hypothesis and in the same direction, has been the subject of several approaches. Besides the inappropriate (in this case Bonferroni procedure, the Fisher's method has been widely used, in particular in population genetics. This last method has nevertheless been challenged by the SGM (symmetry around the geometric mean and Stouffer's Z-transformed methods that are less sensitive to asymmetry and deviations from uniformity of the distribution of the partial P-values. Performances of these different procedures were never compared on proportional data such as those currently used in population genetics. Results We present new software that implements a more recent method, the generalised binomial procedure, which tests for the deviation of the observed proportion of P-values lying under a chosen threshold from the expected proportion of such P-values under the null hypothesis. The respective performances of all available procedures were evaluated using simulated data under the null hypothesis with standard P-values distribution (differentiation tests. All procedures more or less behaved consistently with ~5% significant tests at α = 0.05. Then, linkage disequilibrium tests with increasing signal strength (rate of clonal reproduction, known to generate highly non-standard P-value distributions are undertaken and finally real population genetics data are analysed. In these cases, all procedures appear, more or less equally, very conservative, though SGM seems slightly more conservative. Conclusion Based on our results and those discussed in the literature we conclude that the generalised binomial and Stouffer's Z procedures should be preferred and Z when the number of tests is very small. The more conservative SGM might still be appropriate for meta-analyses when a strong publication bias in favour of significant results is expected to inflate type 2 error.

  15. Negative thermal expansion

    Energy Technology Data Exchange (ETDEWEB)

    Barrera, G D [Departamento de QuImica, Universidad Nacional de la Patagonia SJB, Ciudad Universitaria, 9000 Comodoro Rivadavia (Argentina); Bruno, J A O [Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de QuImica Inorganica, AnalItica y QuImica FIsica, Pabellon 2, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Barron, T H K [School of Chemistry, University of Bristol, Cantock' s Close, Bristol BS8 1TS (United Kingdom); Allan, N L [School of Chemistry, University of Bristol, Cantock' s Close, Bristol BS8 1TS (United Kingdom)

    2005-02-02

    There has been substantial renewed interest in negative thermal expansion following the discovery that cubic ZrW{sub 2}O{sub 8} contracts over a temperature range in excess of 1000 K. Substances of many different kinds show negative thermal expansion, especially at low temperatures. In this article we review the underlying thermodynamics, emphasizing the roles of thermal stress and elasticity. We also discuss vibrational and non-vibrational mechanisms operating on the atomic scale that are responsible for negative expansion, both isotropic and anisotropic, in a wide range of materials. (topical review)

  16. Toward a Negative Anthropology

    OpenAIRE

    Johannssen, Dennis

    2014-01-01

    Can philosophy say what man is? What is gained or lost by making theoretical assumptions about the human being? This essay examines the “negative anthropology” of the early Frankfurt School by asking how Max Horkheimer, Theodor W. Adorno and Ulrich Sonnemann engage with the question “What is man?” Negative anthropology turns out to be more than the critique of philosophical anthropology: By understanding the human being as the ensemble of what it is not, negative anthropology avoids the predi...

  17. Negative transverse impedance

    Energy Technology Data Exchange (ETDEWEB)

    Chou, W.

    1989-06-12

    Recently, measurements in the SPS show that the coherent tune shift in the horizontal direction has positive values whereas that in the vertical direction has negative ones. Thus the existence of negative transverse impedance gets confirmed in a real machine. This stimulates us to start a new round of systematic studies on this interesting phenomenon. The results obtained from our computer simulations are presented in this note. Our simulations demonstrate that the negative transverse impedance may appear when the rotational symmetry embedded in a discontinuity is broken, and that the geometries that we have studies may be the source of the positive horizontal tune shift measured in the SPS.

  18. Holographic Quantum Entanglement Negativity

    CERN Document Server

    Chaturvedi, Pankaj; Sengupta, Gautam

    2016-01-01

    We propose a holographic prescription to compute the entanglement negativity for conformal field theories at finite temperatures which exactly reproduces the entanglement negativity for (1+1)- dimensional conformal field theories at finite temperatures dual to (2+1)- dimensional bulk Euclidean BTZ black holes. We observe that the holographic entanglement negativity captures the distillable pure quantum entanglement and is related to the holographic mutual information. The application of our prescription to higher dimensional conformal field theories at finite temperatures within a $AdS_{d+1}/CFT_{d}$ scenario involving dual bulk $AdS$-Schwarzschild black holes is discussed to elucidate the universality of our conjecture.

  19. Efectos de la simulación computacional en la comprensión de la distribución binomial y la distribución de proporciones

    OpenAIRE

    Martínez, Johanna; Yáñez, Gabriel

    2014-01-01

    En este trabajo se presenta un proyecto de investigación que se basa en el enfoque instrumental para describir el efecto que tiene la simulación computacional en la comprensión de la distribución binomial y la distribución de proporciones.

  20. Isotropic Single Negative Metamaterials

    Directory of Open Access Journals (Sweden)

    P. Protiva

    2008-09-01

    Full Text Available This paper presents the application of simple, and therefore cheap, planar resonators for building 3D isotropic metamaterials. These resonators are: a broadside-coupled split ring resonator with a magnetic response providing negative permeability; an electric dipole terminated by a loop inductor together with a double H-shaped resonator with an electric response providing negative permittivity. Two kinds of 3D isotropic single negative metamaterials are reported. The first material consists of unit cells in the form of a cube bearing on its faces six equal planar resonators with tetrahedral symmetry. In the second material, the planar resonators boxed into spherical plastic shells and randomly distributed in a hosting material compose a real 3D volumetric metamaterial with an isotropic response. In both cases the metamaterial shows negative permittivity or permeability, according to the type of resonators that are used. The experiments prove the isotropic behavior of the cells and of the metamaterial specimens.

  1. Logo and Negative Numbers.

    Science.gov (United States)

    Strawn, Candace A.

    1998-01-01

    Describes LOGO's turtle graphics capabilities based on a sixth-grade classroom's activities with negative numbers and Logo programming. A sidebar explains LOGO and offers suggestions to teachers for using LOGO effectively. (LRW)

  2. Atomic negative ions

    Energy Technology Data Exchange (ETDEWEB)

    Brage, T.

    1991-12-31

    We review some of the recent progress in the studies of alkaline-earth, negative ions. Computations of autodetachment rates, electron affinities and transition wavelengths are discussed and some new and improved results are given.

  3. Atomic negative ions

    Energy Technology Data Exchange (ETDEWEB)

    Brage, T.

    1991-01-01

    We review some of the recent progress in the studies of alkaline-earth, negative ions. Computations of autodetachment rates, electron affinities and transition wavelengths are discussed and some new and improved results are given.

  4. Análisis estadístico para datos de conteo: aplicaciones para el uso de los servicios de salud Statistical analysis for count data: use of healthcare services applications

    Directory of Open Access Journals (Sweden)

    Aarón Salinas-Rodríguez

    2009-10-01

    Full Text Available OBJETIVO: Describir algunos de los modelos estadísticos para el estudio de variables expresadas como un conteo en el contexto del uso de los servicios de salud. MATERIAL Y MÉTODOS: Con base en la Encuesta de Evaluación del Seguro Popular (2005-2006 se calculó el efecto del Seguro Popular sobre el número de consultas externas mediante el uso de los modelos de regresión Poisson, binomial negativo, binomial negativo cero-inflado y Hurdle binomial negativo. Se utilizó el criterio de información de Akaike (AIC para definir el mejor modelo. RESULTADOS: La mejor opción estadística para el análisis del uso de los servicios de salud resultó ser el modelo Hurdle, de acuerdo con sus presuposiciones y el valor del AIC. DISCUSIÓN: La modelación de variables de conteo requiere el empleo de modelos que incluyan una medición de la dispersión. Ante la presencia de exceso de ceros, el modelo Hurdle es una opción apropiada.OBJECTIVE: To describe some of the statistical models for the study of count variables in the context of the use of health services. MATERIAL AND METHODS: We used the Seguro Popular Evaluation Survey to estimate the effect of Seguro Popular on the frequency of use of outpatient health services, using Poisson regression models and negative binomial, zero-inflated negative binomial and the hurdle negative binomial models. We used the Akaike Information Criterion (AIC to define the best model. RESULTS: Results show that the best statistical approach to model the use of health services is the hurdle model, taking into account both the main theoretical assumptions and the statistical results of the AIC. DISCUSSION: The modelling of count data requires the application of statistical models to model data dispersion; in the presence of an excess of zeros, the hurdle model is an appropriate statistical option.

  5. Nedtrykt af negative nyheder

    DEFF Research Database (Denmark)

    Skovsgaard, Morten; Søberg, Pernille Frantz

    2016-01-01

    I adskillige år er det blevet debatteret, hvorvidt nyhedernes negative fokus har konsekvenser for borgerne, og om det i sid-ste ende får flere til at vende ryggen til nyhederne. Vores viden om effekterne af positive og negative nyheder er dog begrænset, og derfor undersøges det i denne artikel......, hvordan henholdsvis positive og negative tv-nyheder påvirker seernes humør, hukom-melse af information fra indslaget og lyst til at se yderligere tv-nyheder. Det gør vi i et survey-eksperiment (N=204), hvor tre grupper så enten et originalt indslag eller det samme indslag klippet med henholdsvis et...

  6. Covariant holographic entanglement negativity

    CERN Document Server

    Chaturvedi, Pankaj; Sengupta, Gautam

    2016-01-01

    We conjecture a holographic prescription for the covariant entanglement negativity of $d$-dimensional conformal field theories dual to non static bulk $AdS_{d+1}$ gravitational configurations in the framework of the $AdS/CFT$ correspondence. Application of our conjecture to a $AdS_3/CFT_2$ scenario involving bulk rotating BTZ black holes exactly reproduces the entanglement negativity of the corresponding $(1+1)$ dimensional conformal field theories and precisely captures the distillable quantum entanglement. Interestingly our conjecture for the scenario involving dual bulk extremal rotating BTZ black holes also accurately leads to the entanglement negativity for the chiral half of the corresponding $(1+1)$ dimensional conformal field theory at zero temperature.

  7. Polemic and Descriptive Negations

    DEFF Research Database (Denmark)

    Horslund, Camilla Søballe

    2011-01-01

    as such may be more or less central to the meaning of the utterance. The present paper investigates the role of morphosyntactic and prosodic prominence as well as register and social setting on the interpretation of negations. It seems plausible to expect that if the negation as such is central to the meaning...... common in certain social context or genres, while polemic negations are more likely to come up in other genres and social settings. Previous studies have shown a relation between articulatory prominence and register, which may further inform the analysis. Hence, the paper investigates how articulatory...... prominence and register may either work in concert or oppose each other with respect to the cues they provide for the interpretation....

  8. 基于β-二项分布的结构易损性分析%Structural fragility estimation with beta-binomial distribution

    Institute of Scientific and Technical Information of China (English)

    刘骁骁; 吴子燕; 王其昂

    2014-01-01

    易损性曲线建立过程中受激励不确定性和结构参数不确定性的影响,会引起结构或构件观测结果的统计相关性。为此,本文提出基于β-二项分布的结构易损性分析方法。该方法根据性能量化指标阈值和 Monte Carlo模拟确定震后观测结果,采用β-二项分布探讨震后观测值的统计相关性;结合对数回归模型,推导了改进β-二项分布的累积分布函数,计算结构失效概率;通过累积对数正态分布拟合易损性曲线,比较了观测失效样本数与观测失效概率统计相关性对易损性的影响,并与未考虑统计相关性的传统易损性曲线作对比。某8层钢筋混凝土框架-剪力墙结构的算例表明,考虑统计相关性的易损性较传统易损性偏大,且结构遭受8度以上地震作用时,考虑失效样本数统计相关性的易损性使预测结果更为保守,利于工程安全。%The uncertainty of seismic excitation and structural parameters in the process of establishing fragility curves leads to statistical dependence among observations,which has been neglected in past applications.In this paper,a new methodology based on beta-binomial distribution to calculate structural fragility is presented.Observations indicating the states (failure or survival)are confirmed via quantita-tive indicators threshold as well as Monte Carlo after each earthquake.Beta-Binomial distribution is ad-dressed to discuss the statistical dependence among observations.Improved cumulative beta-binomial dis-tribution function is derivation to calculate failure probability combined with logistic regression model. Seismic vulnerability curve can be fitted by means of cumulative lognormal distribution,which is com-pared with traditional fragility that of neglecting statistical dependence among observations and fragility curve considering statistical dependence among observed failure rates.A seat eight floors reinforced con

  9. Negative Probabilities and Contextuality

    CERN Document Server

    de Barros, J Acacio; Oas, Gary

    2015-01-01

    There has been a growing interest, both in physics and psychology, in understanding contextuality in experimentally observed quantities. Different approaches have been proposed to deal with contextual systems, and a promising one is contextuality-by-default, put forth by Dzhafarov and Kujala. The goal of this paper is to present a tutorial on a different approach: negative probabilities. We do so by presenting the overall theory of negative probabilities in a way that is consistent with contextuality-by-default and by examining with this theory some simple examples where contextuality appears, both in physics and psychology.

  10. Predictors for Abundance of Host Flea and Floor Flea in Households of Villages with Endemic Commensal Rodent Plague, Yunnan Province, China

    OpenAIRE

    Jia-Xiang Yin; Alan Geater; Virasakdi Chongsuvivatwong; Xing-Qi Dong; Chun-Hong Du; You-Hong Zhong

    2011-01-01

    BACKGROUND: From 1990 to 2006, fifty-five natural villages experienced at least one plague epidemic in Lianghe County, Yunnan Province, China. This study is aimed to document flea abundance and identify predictors in households of villages with endemic commensal rodent plague in Lianghe County. METHODS: Trappings were used to collect fleas and interviews were conducted to gather demography, environmental factors, and other relevant information. Multivariate hurdle negative binomial model was ...

  11. Bayesian reliability demonstration test design for binomial distributed product%成败型产品的Bayes可靠性验证试验设计

    Institute of Scientific and Technical Information of China (English)

    冯文哲; 刘琦

    2012-01-01

    The requirements and constraint conditions of reliability statistical demonstra tion test design for binomial distributed product were analyzed. Considering the producer's risk and consumer's risk, reliability test cost, the reliability test design model based on test loss (RTDMTL) was constructed for the reliability test design of binomial distributed prod- uct. To given sample size, according to 0-1 loss function, the acceptable maximum failure number calculation method was presented under the principle of minimize the posterior ex- pect loss. According to average risk criteria, the formulas of producer's risk and consumer's risk were deduced. To the solution of RTDMTL, the steps of optimum test plan calculating numeric algorithm were given by Matlab software. At last, an example was given to show the validity of the proposed method.%分析了成败型产品的可靠性统计验证试验设计的需求、约束条件.对成败型产品成功概率的假设检验,综合考虑弃真和采伪的风险损失以及可靠性试验的成本,建立了基于试验损失的可靠性试验设计模型(RTDMTL).由Bayes方法,对于给定的样本量,运用0-1损失函数,按照验后期望损失最小的原则,推导出了最大可接受数的计算方法.根据平均风险准则,给出了弃真和采伪两类风险的计算公式.对于RTDMTL的求解,给出了基于Matlab软件的最优试验方案数值算法的求解步骤.最后通过示例验证了该方法的有效性.

  12. Depressionens negative spiral

    DEFF Research Database (Denmark)

    Munk, Karen

    2006-01-01

    Artiklen formidler resultater fra en longitudinel undersøgelse af det selvforstærkende, negative samspil imellem udvikling og vedligeholdelse af alderdomsdepression via primære miljøbelastninger og via  den deprimerede ældre som belastning for miljøet, som i sin tur "svarer negativt" på lidelsen og...

  13. The Negative Repetition Effect

    Science.gov (United States)

    Mulligan, Neil W.; Peterson, Daniel J.

    2013-01-01

    A fundamental property of human memory is that repetition enhances memory. Peterson and Mulligan (2012) recently documented a surprising "negative repetition effect," in which participants who studied a list of cue-target pairs twice recalled fewer targets than a group who studied the pairs only once. Words within a pair rhymed, and…

  14. Macro-level pedestrian and bicycle crash analysis: Incorporating spatial spillover effects in dual state count models.

    Science.gov (United States)

    Cai, Qing; Lee, Jaeyoung; Eluru, Naveen; Abdel-Aty, Mohamed

    2016-08-01

    This study attempts to explore the viability of dual-state models (i.e., zero-inflated and hurdle models) for traffic analysis zones (TAZs) based pedestrian and bicycle crash frequency analysis. Additionally, spatial spillover effects are explored in the models by employing exogenous variables from neighboring zones. The dual-state models such as zero-inflated negative binomial and hurdle negative binomial models (with and without spatial effects) are compared with the conventional single-state model (i.e., negative binomial). The model comparison for pedestrian and bicycle crashes revealed that the models that considered observed spatial effects perform better than the models that did not consider the observed spatial effects. Across the models with spatial spillover effects, the dual-state models especially zero-inflated negative binomial model offered better performance compared to single-state models. Moreover, the model results clearly highlighted the importance of various traffic, roadway, and sociodemographic characteristics of the TAZ as well as neighboring TAZs on pedestrian and bicycle crash frequency.

  15. The Big Date Classfication Mathematical Modeling Based on the Binomial, Poisson Gaussian Random Clustering%基于二项--泊松的高斯随机聚类数学建模稳定性验证

    Institute of Scientific and Technical Information of China (English)

    王志同

    2016-01-01

    Big data clustering process is a gaussian random process, thus in large-scale data classification, build sound data classification model, is very important to improve the ability of mathematical statistics. Binomial, poisson model with global solution of the convex optimization random clustering performance, using binomial, poisson model, the superiority of gaussian random data processing in finite dimensional space, for data clustering analysis. Build the KKT conditions of binomial, poisson model, obtains the binomial, poisson model polynomial kernel, the boundary value of periodic solution of a gaussian clustering feature decomposition, draw Schur complement functional criterion, binomial, poisson model of large-scale data classification system of mathematical statistics, eventually improve the accuracy of the large data clustering. Results show that the derived using binomial, poisson model in the process of gaussian random big data classification is of stable convergence, effectively improves the big data statistics and analysis ability.%大数据的聚类过程是高斯随机过程,因此在大数据分类中,构建稳健的数据分类模型,提高数理统计能力至关重要。二项-泊松模型具有全局解的凸优化随机聚类性能,利用二项-泊松模型对高斯随机性数据处理的优势,在有限维空间中,进行数据聚类分析。构建二项-泊松模型的KKT条件,取得二项-泊松模型的边值周期解多项式核,进行高斯聚类特征分解,得出Schur complement泛函准则,建立二项-泊松模型的数理统计大数据分类系统,最终验证了稳定性。推导结果表明,利用二项-泊松模型在高斯随机大数据分类过程中是稳定收敛的,有效提高了大数据的数理统计和分析能力。

  16. Generalized Divisibility Properties of a Class of Binomial Sums%关于一类二项式和的整除性质的推广

    Institute of Scientific and Technical Information of China (English)

    方露艳

    2008-01-01

    Mare Chamberland和Karl Dilcher[Divisibility properties of a class of binomial sums, J. Number Theory, 120(2006)pp.349-371]研究了一类二项式和uεa,b(n)并给出了一些有趣的性质,其中uεa,b(n)=∑nk=0(-1)εk(nk)a(2nk)b,对a,b,n∈N和ε∈{0,1}.最后,他们提出了uεa,b(n)的一种推广,即uεa,b,c(n)=∑nk=0(-1)εk(nk)a(2nk)b(3nk)c,其中a,b,c,n∈N,ε∈{0,1},期望uεa,b,c(n)具有与uεa,b(n)相似的性质,但并未给出具体的性质及证明.在本文中,我们给出并证明了uεa,b,c(n)的与Wolstenholme定理有关的这部分性质.

  17. 革兰阴性菌耐药%Drug resistance of Gram-negative bacterias

    Institute of Scientific and Technical Information of China (English)

    赵长安

    2016-01-01

    随着抗生素滥用状况的日趋严峻、使用监管的日渐复杂和发现新的尤其是针对革兰阴性菌(GNB)抗生素技术难度的日益增加,GNB 的耐药问题日趋严峻。现主要讨论临床上常见的 GNB 耐药的相关问题。%Along with the condition of antibiotic abuse,the regulatory hurdles to new antibiotics which have be-come increasingly complex and the technical difficulty of discovering new antibiotics,especially those able to penetrate Gram -negative bacteria(GNB),drug -resistant of GNB has become increasingly serious.This review focuses on com-mon clinical GNB drug resistance related issues.

  18. Negative magnetoresistivity in holography

    CERN Document Server

    Sun, Ya-Wen

    2016-01-01

    Negative magnetoresistivity is a special magnetotransport property associated with chiral anomaly in four dimensional chiral anomalous systems, which refers to the transport behavior that the DC longitudinal magnetoresistivity decreases with increasing magnetic field. We calculate the longitudinal magnetoconductivity in the presence of backreactions of the magnetic field to gravity in holographic zero charge and axial charge density systems with and without axial charge dissipation. In the absence of axial charge dissipation, we find that the quantum critical conductivity grows with increasing magnetic field when the backreaction strength is larger than a critical value, in contrast to the monotonically decreasing behavior of quantum critical conductivity in the probe limit. With axial charge dissipation, we find the negative magnetoresistivity behavior. The DC longitudinal magnetoconductivity scales as $B$ in the large magnetic field limit, which deviates from the exact $B^2$ scaling of the probe limit resul...

  19. Negative Emissions Technology

    Science.gov (United States)

    Day, Danny

    2006-04-01

    Although `negative emissions' of carbon dioxide need not, in principle, involve use of biological processes to draw carbon out of the atmosphere, such `agricultural' sequestration' is the only known way to remove carbon from the atmosphere on time scales comparable to the time scale for anthropogenic increases in carbon emissions. In order to maintain the `negative emissions' the biomass must be used in such a way that the resulting carbon dioxide is separated and permanently sequestered. Two options for sequestration are in the topsoil and via geologic carbon sequestration. The former has multiple benefits, but the latter also is needed. Thus, although geologic carbon sequestration is viewed skeptically by some environmentalists as simply a way to keep using fossil fuels---it may be a key part of reversing accelerating climate forcing if rapid climate change is beginning to occur. I will first review the general approach of agricultural sequestration combined with use of resulting biofuels in a way that permits carbon separation and then geologic sequestration as a negative emissions technology. Then I discuss the process that is the focus of my company---the EPRIDA cycle. If deployed at a sufficiently large scale, it could reverse the increase in CO2 concentrations. I also estimate of benefits --carbon and other---of large scale deployment of negative emissions technologies. For example, using the EPRIDA cycle by planting and soil sequestering carbon in an area abut In 3X the size of Texas would remove the amount of carbon that is being accumulated worldwide each year. In addition to the atmospheric carbon removal, the EPRIDA approach also counters the depletion of carbon in the soil---increasing topsoil and its fertility; reduces the excess nitrogen in the water by eliminating the need for ammonium nitrate fertilizer and reduces fossil fuel reliance by providing biofuel and avoiding natural gas based fertilizer production.

  20. Bayesian estimation of parameters for binomial distribution based on the incomplete β-distribution%基于不完全β分布的二项分布参数的Bayesian估计

    Institute of Scientific and Technical Information of China (English)

    赵喜林; 赵煜; 余东

    2014-01-01

    将β分布推广到不完全β分布,给出了二项分布的可靠度的先验分布为不完全β分布时的一些结论,并讨论了在基于二项分布可靠性增长模型中的应用。%The paper extends β-distribution to incomplete β-distribution,and gives some conclusions about the pa-rameters for binomial distribution when its prior distribution to be incompleteβ-distribution,and discusses its appli-cation in reliability growth model based on binomial distribution.

  1. P,Q对称熵损失函数下的二项分布的参数估计%Parameter estimation of binomial distribution under P,Q-symmetric entropy loss function

    Institute of Scientific and Technical Information of China (English)

    崔恩华; 任亮

    2011-01-01

    在P,Q对称损失函数下,讨论二项分布参数θ的Bayes估计及其容许性,并给出了多层Bayes估计具体形式和Bayes置信下限.%Under the P,Q-symmetric entropy loss function,the binomial distribution parameter of Bayes estimate and allowance are given,offers the expression type of the several Bayes estimates and the Bayes believable limit.

  2. Negative refractive index metamaterials

    Directory of Open Access Journals (Sweden)

    Willie J. Padilla

    2006-07-01

    Full Text Available Engineered materials composed of designed inclusions can exhibit exotic and unique electromagnetic properties not inherent in the individual constituent components. These artificially structured composites, known as metamaterials, have the potential to fill critical voids in the electromagnetic spectrum where material response is limited and enable the construction of novel devices. Recently, metamaterials that display negative refractive index – a property not found in any known naturally occurring material – have drawn significant scientific interest, underscoring the remarkable potential of metamaterials to facilitate new developments in electromagnetism.

  3. The Binomial Tree Method for European Option Pricing with Jump Diffusion%基于跳扩散模型欧式期权定价的条件二叉树方法

    Institute of Scientific and Technical Information of China (English)

    石广平; 周圣武

    2012-01-01

    对股票价格的跳扩散模型进行了分析,在CRR二叉树期权定价模型的基础上考虑标的股票价格发生跳跃的情况,得出基于跳扩散过程的股票期权的条件二叉树定价模型,并且证明在极限情况下,该条件二叉树模型的期权定价公式趋于Merton的解析定价公式,数值试验证实该条件二叉树模型的有效性。%The European option pricing problem when the underlying stock price follow jump - diffusion is studied using binomial tree method, and the binomial tree pricing formula for European option is obtained. It is proved that the equation of European option value under binomial tree model is quickly converged at Merton' s accurate analytical solution. Numerical examples illustrate the model' s accuracy.

  4. Valoración probabilística versus borrosa, opciones reales y el modelo binomial. Aplicación para proyectos de inversión en condiciones de ambigüedad

    Directory of Open Access Journals (Sweden)

    Gastón Silverio Milanesi

    2014-01-01

    Full Text Available El trabajo tiene por objeto exponer la metodología, las ventajas y las debilidades del modelo binomial borroso de valoración de opciones reales como complemento del modelo binomial probabilístico. Para lograr lo anterior primero se presentan los modelos de opciones reales clasificados en probabilístico y borroso; luego se desarrolla el modelo binomial borroso incorporando: el método Marketed Asset Disclai- mer (MAD, rejillas binomiales borrosas y el índice pesimismo-optimismo, para estimar el valor esperado de las opciones del proyecto (VEOP. Se ilustra con un caso comparando los resultados obtenidos con el modelo borroso y el probabilístico. Finalmente se concluye que, en situaciones de falta de información (ambigüedad, la lógica borrosa es un complemento del modelo probabilístico para determinar el valor de la flexibilidad estratégica. © 2012 Universidad ICESI. Publicado por Elsevier España, S.L. Todos los derechos reservados.

  5. The binomial distribution of hydrogen and deuterium in arsanes, diarsanes, and triarsanes generated from As(III)/[BH(n)D(4-n)]- and the effect of trace amounts of Rh(III) ions.

    Science.gov (United States)

    Pagliano, Enea; D'Ulivo, Alessandro; Mester, Zoltán; Sturgeon, Ralph E; Meija, Juris

    2012-12-01

    Recent studies of the formation of arsane in the borohydride/arsenate reaction demonstrate the occurrence of condensation cascades whereby small quantities of di- and triarsanes are formed. In this study, the isotopic composition of these di- and triarsanes was examined using deuterium labelled borohydrides. A statistical model was employed to construct the mass spectra of all diarsane and triarsane isotopologues (As(2)H(n)D(4-n) and As(3)H(n)D(5-n)) from the mass spectra of isotopically pure compounds (As(2)H(4), As(2)D(4), As(3)H(5), and As(3)D(5)). Subsequent deconvolution of the experimental mixed spectra shows that incorporation of hydrogen closely follows the binomial distribution, in accord with arsane formation. The H/D distribution in arsane, diarsane, and triarsane isotopologues is binomial in the absence of any interference. However, this is significantly altered by the presence of some transition metals; presented here, for the first time, are the effects of Rh(III). The presence of Rh(III) in the As(III)/[BD(4)](-) system entails the incorporation of hydrogen into the arsanes arising from the solvent, altering the expected binomial H/D distribution.

  6. Negative Average Preference Utilitarianism

    Directory of Open Access Journals (Sweden)

    Roger Chao

    2012-03-01

    Full Text Available For many philosophers working in the area of Population Ethics, it seems that either they have to confront the Repugnant Conclusion (where they are forced to the conclusion of creating massive amounts of lives barely worth living, or they have to confront the Non-Identity Problem (where no one is seemingly harmed as their existence is dependent on the “harmful” event that took place. To them it seems there is no escape, they either have to face one problem or the other. However, there is a way around this, allowing us to escape the Repugnant Conclusion, by using what I will call Negative Average Preference Utilitarianism (NAPU – which though similar to anti-frustrationism, has some important differences in practice. Current “positive” forms of utilitarianism have struggled to deal with the Repugnant Conclusion, as their theory actually entails this conclusion; however, it seems that a form of Negative Average Preference Utilitarianism (NAPU easily escapes this dilemma (it never even arises within it.

  7. Negative leave balances

    CERN Multimedia

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1Â September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply. Â Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30Â September and/or 31Â December, leave will automatically be transferred from one account to another on the relevant dates i...

  8. Negative leave balances

    CERN Multimedia

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1 September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply.  Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30 September and/or 31 December, leave will automatically be transferred from one account to another on the relevant dates in or...

  9. Cosmology With Negative Potentials

    CERN Document Server

    Felder, G; Kofman, L A; Linde, Andrei D; Felder, Gary; Frolov, Andrei; Kofman, Lev; Linde, Andrei

    2002-01-01

    We investigate cosmological evolution in models where the effective potential V(\\phi) may become negative for some values of the field \\phi. Phase portraits of such theories in space of variables (\\phi,\\dot\\phi,H) have several qualitatively new features as compared with phase portraits in the theories with V(\\phi) > 0. Cosmological evolution in models with potentials with a "stable" minimum at V(\\phi)<0 is similar in some respects to the evolution in models with potentials unbounded from below. Instead of reaching an AdS regime dominated by the negative vacuum energy, the universe reaches a turning point where its energy density vanishes, and then it contracts to a singularity with properties that are practically independent of V(\\phi). We apply our methods to investigation of the recently proposed cyclic universe scenario. We show that in addition to the singularity problem there are other problems that need to be resolved in order to realize a cyclic regime in this scenario. We propose several modificati...

  10. Polarized negative ions

    Energy Technology Data Exchange (ETDEWEB)

    Haeberli, W.

    1981-04-01

    This paper presents a survey of methods, commonly in use or under development, to produce beams of polarized negative ions for injection into accelerators. A short summary recalls how the hyperfine interaction is used to obtain nuclear polarization in beams of atoms. Atomic-beam sources for light ions are discussed. If the best presently known techniques are incorporated in all stages of the source, polarized H/sup -/ and D/sup -/ beams in excess of 10 ..mu..A can probably be achieved. Production of polarized ions from fast (keV) beams of polarized atoms is treated separately for atoms in the H(25) excited state (Lamb-Shift source) and atoms in the H(1S) ground state. The negative ion beam from Lamb-Shift sources has reached a plateau just above 1 ..mu..A, but this beam current is adequate for many applications and the somewhat lower beam current is compensated by other desirable characteristics. Sources using fast polarized ground state atoms are in a stage of intense development. The next sections summarize production of polarized heavy ions by the atomic beam method, which is well established, and by optical pumping, which has recently been demonstrated to yield very large nuclear polarization. A short discussion of proposed ion sources for polarized /sup 3/He/sup -/ ions is followed by some concluding remarks.

  11. Classroom Management and Negative Reinforcement.

    Science.gov (United States)

    Tauber, Robert T.

    Of the four simple consequences for behavior, none is more misunderstood than negative reinforcement. A Negative Reinforcement Quiz administered to 233 student teachers from two universities revealed that the vast majority of respondents mistakenly viewed negative reinforcement as a synonym for punishment, and believe that negative reinforcement…

  12. On Translation of Negative Sentences

    Institute of Scientific and Technical Information of China (English)

    谭利彬

    2007-01-01

    The English language has its peculiarities in negation.And the method of negation in English is quite different from that in Chinese.In order to fully understand the negative sentence in English,we should make clear the classification and key points of negation first.

  13. On Translation of Negative Sentences

    Institute of Scientific and Technical Information of China (English)

    谭利彬

    2007-01-01

    The English language has its peculiarities in negation. And the method of negation in English is quite different from that in Chinese. In order to fully understand the negative sentence in English, we should make clear the classification and key points of negation first.

  14. Ecological effects of the invasive giant madagascar day gecko on endemic mauritian geckos: applications of binomial-mixture and species distribution models.

    Science.gov (United States)

    Buckland, Steeves; Cole, Nik C; Aguirre-Gutiérrez, Jesús; Gallagher, Laura E; Henshaw, Sion M; Besnard, Aurélien; Tucker, Rachel M; Bachraz, Vishnu; Ruhomaun, Kevin; Harris, Stephen

    2014-01-01

    The invasion of the giant Madagascar day gecko Phelsuma grandis has increased the threats to the four endemic Mauritian day geckos (Phelsuma spp.) that have survived on mainland Mauritius. We had two main aims: (i) to predict the spatial distribution and overlap of P. grandis and the endemic geckos at a landscape level; and (ii) to investigate the effects of P. grandis on the abundance and risks of extinction of the endemic geckos at a local scale. An ensemble forecasting approach was used to predict the spatial distribution and overlap of P. grandis and the endemic geckos. We used hierarchical binomial mixture models and repeated visual estimate surveys to calculate the abundance of the endemic geckos in sites with and without P. grandis. The predicted range of each species varied from 85 km2 to 376 km2. Sixty percent of the predicted range of P. grandis overlapped with the combined predicted ranges of the four endemic geckos; 15% of the combined predicted ranges of the four endemic geckos overlapped with P. grandis. Levin's niche breadth varied from 0.140 to 0.652 between P. grandis and the four endemic geckos. The abundance of endemic geckos was 89% lower in sites with P. grandis compared to sites without P. grandis, and the endemic geckos had been extirpated at four of ten sites we surveyed with P. grandis. Species Distribution Modelling, together with the breadth metrics, predicted that P. grandis can partly share the equivalent niche with endemic species and survive in a range of environmental conditions. We provide strong evidence that smaller endemic geckos are unlikely to survive in sympatry with P. grandis. This is a cause of concern in both Mauritius and other countries with endemic species of Phelsuma.

  15. Relationship between Fire-Danger Weather and Forest Fire in Qiannan Area%黔南地区气象因子与森林火灾发生次数之间的关系

    Institute of Scientific and Technical Information of China (English)

    肖云丹; 鞠洪波; 张雄清; 纪平

    2011-01-01

    In this study, based on data of the forest fire occurrence and meteorological variables in spring fireproofing period in Qiannan area, Poisson regression model, negative binomial model, zero-inflated negative binomial model and Hurdle model were respectively employed to predict the forest fires under fire-danger climate, and those models were compared with each other based on the prediction. The results showed that; Poisson regression model did not fit well into the over-dispersion data. Negative binomial distribution fitted better into the data than Poisson distribution. But both of them were not suitable for simulating zero drived dispersion data. Zero-inflated negative binomial regression model and Hurdle model were useful methods for such data. Zero inflated negative binomial regression model and Hurdle model performed better than other two models in predicting forest fires. Moreover, Hurdle model was even superior to zero-inflated negative binomial model.%对黔南区春季防火期森林火灾数据进行分析,分别引入Poisson回归模型、负二项模型、零膨胀负二项模型和Hurdle模型拟合该地区火险天气森林火灾发生数,并对这些模型进行逐步筛选.结果表明:Poisson回归模型不适用于处理过度离散的数据,负二项回归模型相对于Poisson回归模型,比较适用于过离散数据;但是对于零个数过多的数据,这2类模型拟合效果较差,零膨胀负二项模型和Hurdle模型对这类数据有很好的解决办法.零膨胀负二项模型和Hurdle模型拟合效果优于其他2种模型,而且Hurdle模型好于零膨胀负二项模型.

  16. Primitive Virtual Negative Charge

    CERN Document Server

    Kim, Kiyoung

    2008-01-01

    Physical fields, such as gravity and electromagnetic field, are interpreted as results from rearrangement of vacuum particles to get the equilibrium of net charge density and net mass density in 4-dimensional complex space. Then, both fields should interact to each other in that physical interaction is considered as a field-to-field interaction. Hence, Mass-Charge interaction is introduced with primitive-virtual negative charge defined for the mass. With the concept of Mass-Charge interaction electric equilibrium of the earth is discussed, especially about the electric field and magnetic field of the earth. For unsettled phenomena related with the earth's gravity, such as antigravity phenomenon, gravity anomalies during the solar eclipses, the connection between geomagnetic storms and earthquakes, etc., possible explanations are discussed.

  17. Negative optical torque.

    Science.gov (United States)

    Chen, Jun; Ng, Jack; Ding, Kun; Fung, Kin Hung; Lin, Zhifang; Chan, C T

    2014-09-17

    Light carries angular momentum, and as such it can exert torques on material objects. Applications of these opto-mechanical effects were limited initially due to their smallness in magnitude, but later becomes powerful and versatile after the invention of laser. Novel and practical approaches for harvesting light for particle rotation have since been demonstrated, where the structure is always subjected to a positive optical torque along a certain axis if the incident angular momentum has a positive projection on the same axis. We report here an interesting phenomenon of "negative optical torque", meaning that incoming photons carrying angular momentum rotate an object in the opposite sense. Surprisingly this can be realized quite straightforwardly in simple planar structures. Field retardation is a necessary condition and discrete rotational symmetry of material object plays an important role. The optimal conditions are explored and explained.

  18. 男大学生对跨栏跑运动的态度、动机调查与对策%Investigation and Countermeasures on Hurdling Attitudes and Motivation of Male Undergraduates

    Institute of Scientific and Technical Information of China (English)

    杨志宏

    2016-01-01

    By using literature,questionnaire survey and mathematical statistics methods and combining daily teaching and training routine,this paper investigates,counts and analyzes the attitudes and motivation on hurdling among male undergraduates from non-sport departments in Hunan Province,and at the same time,discussed the countermeasures.%主要运用文献资料法、问卷调查法、数理统计等方法,结合日常体育教学与训练工作实践,对湖南省高校普通院系男大学生对跨栏跑运动的态度、动机进行了调查、统计与分析,同时探讨了对策。

  19. Negative Expertise: Comparing Differently Tenured Elder Care Nurses' Negative Knowledge

    Science.gov (United States)

    Gartmeier, Martin; Lehtinen, Erno; Gruber, Hans; Heid, Helmut

    2011-01-01

    Negative expertise is conceptualised as the professional's ability to avoid errors during practice due to certain cognitive agencies. In this study, negative knowledge (i.e. knowledge about what is wrong in a certain context and situation) is conceptualised as one such agency. This study compares and investigates the negative knowledge of elder…

  20. Large negative lateral shifts due to negative refraction

    CERN Document Server

    Benedicto, Jessica; Moreau, Antoine; Centeno, Emmanuel

    2011-01-01

    When a thin structure in which negative refraction occurs (a metallo-dielectric or a photonic crystal) is illuminated by a beam, the reflected and transmitted beam can undergo a large negative lateral shift. This phenomenon can be seen as an interferential enhancement of the geometrical shift and can be considered as a signature of negative refraction.

  1. Coagulase-Negative Staphylococci

    Science.gov (United States)

    Heilmann, Christine; Peters, Georg

    2014-01-01

    SUMMARY The definition of the heterogeneous group of coagulase-negative staphylococci (CoNS) is still based on diagnostic procedures that fulfill the clinical need to differentiate between Staphylococcus aureus and those staphylococci classified historically as being less or nonpathogenic. Due to patient- and procedure-related changes, CoNS now represent one of the major nosocomial pathogens, with S. epidermidis and S. haemolyticus being the most significant species. They account substantially for foreign body-related infections and infections in preterm newborns. While S. saprophyticus has been associated with acute urethritis, S. lugdunensis has a unique status, in some aspects resembling S. aureus in causing infectious endocarditis. In addition to CoNS found as food-associated saprophytes, many other CoNS species colonize the skin and mucous membranes of humans and animals and are less frequently involved in clinically manifested infections. This blurred gradation in terms of pathogenicity is reflected by species- and strain-specific virulence factors and the development of different host-defending strategies. Clearly, CoNS possess fewer virulence properties than S. aureus, with a respectively different disease spectrum. In this regard, host susceptibility is much more important. Therapeutically, CoNS are challenging due to the large proportion of methicillin-resistant strains and increasing numbers of isolates with less susceptibility to glycopeptides. PMID:25278577

  2. Negative Refraction at Visible Frequencies

    National Research Council Canada - National Science Library

    Henri J. Lezec; Jennifer A. Dionne; Harry A. Atwater

    2007-01-01

    .... We demonstrate an experimental realization of a two-dimensional negative-index material in the blue-green region of the visible spectrum, substantiated by direct geometric visualization of negative refraction...

  3. The case for negative senescence

    DEFF Research Database (Denmark)

    Vaupel, James W; Baudisch, Annette; Dölling, Martin

    2004-01-01

    kinds of animals that may experience negative senescence and conclude that negative senescence may be widespread, especially in indeterminate-growth species for which size and fertility increase with age. We develop optimization models of life-history strategies that demonstrate that negative senescence...

  4. Estudo por simulação Monte Carlo de um estimador robusto utilizado na inferência de um modelo binomial contaminado = A Monte Carlo simulation study of a robust estimator used in the inference of a contaminated binomial model

    Directory of Open Access Journals (Sweden)

    Marcelo Angelo Cirillo

    2010-07-01

    Full Text Available A inferencia estatistica em populacoes binomiais contaminadas esta sujeita a erros grosseiros de estimacao, uma vez que as amostras nao sao identicamente distribuidas. Por esse problema, este trabalho tem por objetivo determinar qual a melhor constante de afinidade (c1 que proporcione melhor desempenho em um estimador pertencente a classedos estimadores-E. Com esse proposito, neste trabalho, foi utilizada a metodologia, considerando-se o metodo de simulacao Monte Carlo, no qual diferentes configuracoes descritas pela combinacao de valores parametricos, niveis de contaminacao e tamanhos de amostra foram avaliados. Concluiu-se que, para alta probabilidade de mistura (ƒÁ = 0,40, recomenda-se assumir c1 = 0,1 nas situacoes de grandes amostras (n = 50 e n = 80. The statistical inference in binomial population is subject to gross errors of estimate, as the samples are not identically distributed. Due to this problem, this work aims to determine which is the best affinity constant (c1 that provides the best performance in the estimator, belonging to the class of E-estimators. With that purpose, the methodology used in this work was applied considering the Monte Carlo simulation method, in which different configurations described by combination of parametric values, levels of contamination and sample sizes were appraised. It was concluded that for the high probability of contamination (ƒÁ = 0.40, c1 = 0.1 is recommended in cases with large samples (n = 50 and n = 80.

  5. Negative ions in liquid helium

    Science.gov (United States)

    Khrapak, A. G.; Schmidt, W. F.

    2011-05-01

    The structure of negative ions in liquid 4He is analyzed. The possibility of cluster or bubble formation around impurity ions of both signs is discussed. It is shown that in superfluid helium, bubbles form around negative alkaline earth metal ions and clusters form around halogen ions. The nature of "fast" and "exotic" negative ions is also discussed. It is assumed that "fast" ions are negative ions of helium excimer molecules localized inside bubbles. "Exotic" ions are stable negative impurity ions, which are always present in small amounts in gas discharge plasmas. Bubbles or clusters with radii smaller the radius of electron bubbles develop around these ions.

  6. The negation bias: when negations signal stereotypic expectancies.

    Science.gov (United States)

    Beukeboom, Camiel J; Finkenauer, Catrin; Wigboldus, Daniël H J

    2010-12-01

    Research on linguistic biases shows that stereotypic expectancies are implicitly reflected in language and are thereby subtly communicated to message recipients. We examined whether these findings extend to the use of negations (e.g., not smart instead of stupid). We hypothesized that people use more negations in descriptions of stereotype-inconsistent behavior than in descriptions of stereotype-consistent behavior. In 3 studies, participants either judged the applicability of experimentally controlled person descriptions or spontaneously produced person descriptions themselves. Results provided support for this hypothesis. Moreover, a 4th study demonstrated that negations have communicative consequences. When a target person's behavior was described with negations, message recipients inferred that this behavior was an exception to the rule and that it was more likely caused by situational circumstances than by dispositional factors. These findings indicate that by using negations people implicitly communicate stereotypic expectancies and that negations play a subtle but powerful role in stereotype maintenance.

  7. The p-adic Riemann Hypothesis of Exponential Sums Associated to Certain Binomials over Finite Fields%有限域上一类二项式的带扭指数和的P进黎曼假设

    Institute of Scientific and Technical Information of China (English)

    牛传择

    2011-01-01

    通过研究带扭的T进指数和,给出有限域上一类二项式带扭指数的L函数的牛顿折线的一个下界,并且所给的下界优于经典的Hodge界.%According to study the twisted T-adic exponential sums,an explicit arithmetic polygon was show to be the lower bound of the Newton polygon of the L-function of the exponential sums associated to certain binomials over finite fields.Moreover,the given bound is better than the classical Hodge bound.

  8. The Equal Relationship between Classical Estimation and Bayesian Estimation of a Binomial Distribution%二项分布参数的经典估计与 Bayes 估计相等的关系

    Institute of Scientific and Technical Information of China (English)

    姚丽

    2014-01-01

    证明了二项分布中未知参数的经典估计(最大似然估计和矩估计),一定存在一个先验分布,使其贝叶斯估计就是该经典估计的结论。%The presence of a prior distribution was proved .For binomial distribution under this prior dis-tribution , the classical estimation and the Bayesian estimation of the unknown parameter are equal .

  9. Ruin Probability and Asymptotic Estimate of a Compound Binomial Distribution Model%复合二项分布模型的破产概率及其渐近估计

    Institute of Scientific and Technical Information of China (English)

    许璐; 赵闻达

    2012-01-01

    运用古典概率的有关知识,通过建立合适的数学模型导出了复合二项分布的破产概率的显式解,进而得到了它的渐近估计表达式。所得结论包含了有关文献的结果。%The classical probability theory is used to derive solution of the ultimate ruin prob- ability in a compound binomial distribution model, and its asymptotic estimation is obtained. The conclusion has improved the result in related literature.

  10. 具有跳扩散的美式期权二叉树计算格式的收敛速率%ON THE CONVERGENCE RATE OF THE BINOMIAL TREE SCHEME FOR AN AMERICAN OPTION WITH JUMP-DIFFUSION

    Institute of Scientific and Technical Information of China (English)

    梁进

    2008-01-01

    American put option with jump-diffusion can be modelled as a vari-ational inequality problem with an integral term.Under the stability conditionσ2△t/△x2≤1,where △x=lnSn+1/Sn,the cnvergence rate O((△)2/3+(△t1/3)of theexplicit finite scheme for this problem is obtained by using penalization technique.The binomial tree scheme of this model,which is equivalent to the explicit scheme,is convergent by the same rate.

  11. Exploring the effects of roadway characteristics on the frequency and severity of head-on crashes: case studies from Malaysian federal roads.

    Science.gov (United States)

    Hosseinpour, Mehdi; Yahaya, Ahmad Shukri; Sadullah, Ahmad Farhan

    2014-01-01

    Head-on crashes are among the most severe collision types and of great concern to road safety authorities. Therefore, it justifies more efforts to reduce both the frequency and severity of this collision type. To this end, it is necessary to first identify factors associating with the crash occurrence. This can be done by developing crash prediction models that relate crash outcomes to a set of contributing factors. This study intends to identify the factors affecting both the frequency and severity of head-on crashes that occurred on 448 segments of five federal roads in Malaysia. Data on road characteristics and crash history were collected on the study segments during a 4-year period between 2007 and 2010. The frequency of head-on crashes were fitted by developing and comparing seven count-data models including Poisson, standard negative binomial (NB), random-effect negative binomial, hurdle Poisson, hurdle negative binomial, zero-inflated Poisson, and zero-inflated negative binomial models. To model crash severity, a random-effect generalized ordered probit model (REGOPM) was used given a head-on crash had occurred. With respect to the crash frequency, the random-effect negative binomial (RENB) model was found to outperform the other models according to goodness of fit measures. Based on the results of the model, the variables horizontal curvature, terrain type, heavy-vehicle traffic, and access points were found to be positively related to the frequency of head-on crashes, while posted speed limit and shoulder width decreased the crash frequency. With regard to the crash severity, the results of REGOPM showed that horizontal curvature, paved shoulder width, terrain type, and side friction were associated with more severe crashes, whereas land use, access points, and presence of median reduced the probability of severe crashes. Based on the results of this study, some potential countermeasures were proposed to minimize the risk of head-on crashes.

  12. Negative snakes in JET: evidence for negative shear

    Energy Technology Data Exchange (ETDEWEB)

    Gill, R.D.; Alper, B.; Edwards, A.W. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Pearson, D. [Reading Univ. (United Kingdom)

    1994-07-01

    The signature of the negative snakes from the soft X-ray cameras is very similar to the more usual snakes except that the localised region of the snake has, compared with its surroundings, decreased rather than increased emission. Circumstances where negative snakes have been seen are reviewed. The negative snake appears as a region of increased resistance and of increased impurity density. The relationship between the shear and the current perturbation is shown, and it seem probable that the magnetic shear is reversed at the point of the negative snake, i.e. that q is decreasing with radius. 6 refs., 6 figs.

  13. Research on Relation between Reaction Time and Performance of Sprint and Hurdle%田径短跨项目起跑反应时与运动成绩关联的研究

    Institute of Scientific and Technical Information of China (English)

    姜宏斌

    2016-01-01

    ,except for male and female 100m and 100m hurdles ,110m hurdle ,there are certain significant differences between different sports events .2) Except for significant difference of reaction time in the women's 200m qualifica‐tion round ,semifinal and final ,there are no differences in other events .3) There are significant correlation between the male and female 100m ,200m reaction time and performance .4) Excellent athletes can keep a lower level of reaction time .The basic way to improve the performance of sprint and hurdle is to realize the operation mechanism and function of reaction time scientifically ,improve the sports skill and strength fitness ,and actively implement psychological intervention .

  14. Negative hydrogen ion production mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Bacal, M. [UPMC, LPP, Ecole Polytechnique, UMR CNRS 7648, Palaiseau (France); Wada, M. [School of Science and Engineering, Doshisha University, Kyoto 610-0321 (Japan)

    2015-06-15

    Negative hydrogen/deuterium ions can be formed by processes occurring in the plasma volume and on surfaces facing the plasma. The principal mechanisms leading to the formation of these negative ions are dissociative electron attachment to ro-vibrationally excited hydrogen/deuterium molecules when the reaction takes place in the plasma volume, and the direct electron transfer from the low work function metal surface to the hydrogen/deuterium atoms when formation occurs on the surface. The existing theoretical models and reported experimental results on these two mechanisms are summarized. Performance of the negative hydrogen/deuterium ion sources that emerged from studies of these mechanisms is reviewed. Contemporary negative ion sources do not have negative ion production electrodes of original surface type sources but are operated with caesium with their structures nearly identical to volume production type sources. Reasons for enhanced negative ion current due to caesium addition to these sources are discussed.

  15. Negative hydrogen ion production mechanisms

    Science.gov (United States)

    Bacal, M.; Wada, M.

    2015-06-01

    Negative hydrogen/deuterium ions can be formed by processes occurring in the plasma volume and on surfaces facing the plasma. The principal mechanisms leading to the formation of these negative ions are dissociative electron attachment to ro-vibrationally excited hydrogen/deuterium molecules when the reaction takes place in the plasma volume, and the direct electron transfer from the low work function metal surface to the hydrogen/deuterium atoms when formation occurs on the surface. The existing theoretical models and reported experimental results on these two mechanisms are summarized. Performance of the negative hydrogen/deuterium ion sources that emerged from studies of these mechanisms is reviewed. Contemporary negative ion sources do not have negative ion production electrodes of original surface type sources but are operated with caesium with their structures nearly identical to volume production type sources. Reasons for enhanced negative ion current due to caesium addition to these sources are discussed.

  16. On core strength training of women's 100m hurdles athletes%女子100米栏运动员核心力量训练研究

    Institute of Scientific and Technical Information of China (English)

    刘静; 杨合适

    2012-01-01

    主要采用高速摄影与运动录像解析法与实验法,对四川成都九名女子100米栏运动员8周的核心力量训练,通过训练前后对比分析研究发现:运动员身体素质与核心稳定能力水平有显著性提高,特别是髋关节灵活性及核心稳定性有非常显著性提高;运动员身体重心在栏上的运动轨迹有明显变化,主要表现为身体重心垂直投影点与栏的水平距离缩小,身体重心与栏的垂直距离变小,躯干前倾角变小,身体重心在垂直方向的位移变小;运动员对个人体能水平的控制能力有一定程度的提高,这主要表现在个人技术水平与现有体能水平的合理分配,也就是个人体能能力向技术水平提高的正迁移比例增加,起跨技术也有明显提高,着地技术虽有所改善但还有待于提高。%With the methods of high-speed photography,video analysis and experiment,the paper made a comparative analysis of 9 women's 100m hurdles athletes from Chengdu and Sichuan before and after the core strength training.After training,there was significant improvement in athletes' physical fitness and core stability,especially in the hip flexibility and core stability.There are obvious changes in the movement orbit of gravity centre,including the smaller horizontal and vertical distance between vertical projection of gravity center and hurdle,smaller trunk anteversion and vertical displacement of gravity centre.The athletes had better ability in controlling personal fitness,which is manifested in reasonable allocation of individual skill level and physical strength as well as the improved skill in taking off and landing.

  17. Wages, Amenities and Negative Attitudes

    DEFF Research Database (Denmark)

    Waisman, Gisela; Larsen, Birthe

    We exploit the regional variation in negative attitudes towards immigrants to Sweden in order to analyse the consequences of the attitudes on immigrants welfare. We find that attitudes towards immigrants are of importance: they both affect their labour market outcomes and their quality of life. We...... interpret the negative effect on wages as evidence of labour market discrimination. We estimate the welfare effects of negative attitudes, through their wage and local amenities, for immigrants with different levels of skills, origin, gender and age....

  18. On Negation as Mitigation: The Case of Negative Irony

    Science.gov (United States)

    Giora, Rachel; Fein, Ofer; Ganzi, Jonathan; Levi, Natalie Alkeslassy; Sabah, Hadas

    2005-01-01

    Four experiments support the view of negation as mitigation (Giora, Balaban, Fein, & Alkabets, 2004). They show that when irony involves some sizable gap between what is said and what is criticized (He is exceptionally bright said of an idiot), it is rated as highly ironic (Giora, 1995). A negated version of that overstatement (He is not…

  19. Causality, Nonlocality, and Negative Refraction.

    Science.gov (United States)

    Forcella, Davide; Prada, Claire; Carminati, Rémi

    2017-03-31

    The importance of spatial nonlocality in the description of negative refraction in electromagnetic materials has been put forward recently. We develop a theory of negative refraction in homogeneous and isotropic media, based on first principles, and that includes nonlocality in its full generality. The theory shows that both dissipation and spatial nonlocality are necessary conditions for the existence of negative refraction. It also provides a sufficient condition in materials with weak spatial nonlocality. These fundamental results should have broad implications in the theoretical and practical analyses of negative refraction of electromagnetic and other kinds of waves.

  20. Neurobiological background of negative symptoms.

    Science.gov (United States)

    Galderisi, Silvana; Merlotti, Eleonora; Mucci, Armida

    2015-10-01

    Studies investigating neurobiological bases of negative symptoms of schizophrenia failed to provide consistent findings, possibly due to the heterogeneity of this psychopathological construct. We tried to review the findings published to date investigating neurobiological abnormalities after reducing the heterogeneity of the negative symptoms construct. The literature in electronic databases as well as citations and major articles are reviewed with respect to the phenomenology, pathology, genetics and neurobiology of schizophrenia. We searched PubMed with the keywords "negative symptoms," "deficit schizophrenia," "persistent negative symptoms," "neurotransmissions," "neuroimaging" and "genetic." Additional articles were identified by manually checking the reference lists of the relevant publications. Publications in English were considered, and unpublished studies, conference abstracts and poster presentations were not included. Structural and functional imaging studies addressed the issue of neurobiological background of negative symptoms from several perspectives (considering them as a unitary construct, focusing on primary and/or persistent negative symptoms and, more recently, clustering them into factors), but produced discrepant findings. The examined studies provided evidence suggesting that even primary and persistent negative symptoms include different psychopathological constructs, probably reflecting the dysfunction of different neurobiological substrates. Furthermore, they suggest that complex alterations in multiple neurotransmitter systems and genetic variants might influence the expression of negative symptoms in schizophrenia. On the whole, the reviewed findings, representing the distillation of a large body of disparate data, suggest that further deconstruction of negative symptomatology into more elementary components is needed to gain insight into underlying neurobiological mechanisms.

  1. Income, Amenities and Negative Attitudes

    DEFF Research Database (Denmark)

    Waisman, Gisela; Larsen, Birthe

    2016-01-01

    ’ quality of life, they also affect their income. We estimate the utility effects of negative attitudes for refugees with different levels of education and gender. We also analyse how the size of the refugees’ networks relate to their quality of life and income as well as how negative attitudes towards......We exploit the regional variation in negative attitudes towards immigrants to Sweden in order to analyse the consequences of negative attitudes on refugees’ utility from labour income and amenities. We find that attitudes towards immigrants are important: while they affect mainly the refugees...

  2. Prestarlike functions with negative coefficients

    Directory of Open Access Journals (Sweden)

    H. Silverman

    1979-01-01

    Full Text Available The extreme points for prestarlike functions having negative coefficients are determined. Coefficient, distortion and radii of univalence, starlikeness, and convexity theorems are also obtained.

  3. Brain representations of negative numbers.

    Science.gov (United States)

    Parnes, Michael; Berger, Andrea; Tzelgov, Joseph

    2012-12-01

    Participants performed a physical comparison task of pairs of positive and pairs of negative one-digit numbers while their electrophysiological brain activity was measured. The numerical value of the presented digits was either congruent or incongruent with the physical size of the digits. Analysis has shown that the earliest event-related potential (ERP) difference between positive and negative numbers was found in the P300 ERP component peak, where there was an inverse effect of congruity in the negative pairs, compared with the positive ones. This pattern of results supports the idea that natural numbers serve as primitives of the human cognitive system, whereas negative numbers are apparently generated if needed.

  4. Neuroimaging correlates of negative priming.

    Science.gov (United States)

    Steel, C; Haworth, E J; Peters, E; Hemsley, D R; Sharma, T; Gray, J A; Pickering, A; Gregory, L; Simmons, A; Bullmore, E T; Williams, S C

    2001-11-16

    Many theoretical accounts of selective attention and memory retrieval include reference to active inhibitory processes, such as those argued to underlie the negative priming effect. fMRI was used in order to investigate the areas of cortical activation associated with Stroop interference, Stroop facilitation and Stroop negative priming tasks. The most significant activation within the negative priming task was within the inferior parietal lobule, left temporal lobe and frontal lobes. Areas of cortical activation are discussed with reference to theoretical accounts of the negative priming effect.

  5. Be Aware of Negative Reinforcement.

    Science.gov (United States)

    Cipani, Ennio C.

    1995-01-01

    This article examines the concept of negative reinforcement in relation to the maintenance of off-task and disruptive behaviors in classrooms. Suggestions are given for determining whether negative reinforcement (in the form of escape from the instructional task) or teacher attention is maintaining the behavior. Suggestions for making tasks less…

  6. Negative supervisionsoplevelser og deres konsekvenser

    DEFF Research Database (Denmark)

    Nielsen, Jan

    2011-01-01

    in evaluation. First part of the paper explores negative experience in supervision in general. The second part, focusing on negative experience in supervision caused by evaluation, is explored and discussed in relation to the key concept of supervisory alliance (Bordin, 1983), perceiving evaluation...

  7. Negative phototropism of rice root

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@It is often believed that the stem of higher plants has characteristics of positive phototropism, and the root shows no phototropism or no sensitivity to light though the root of Arabdopsis was reported possessing characteristics of negative phototropism. In this study, a distinct negative phototropism of the root system of rice seedlings was observed.

  8. Negative refraction in outer space?

    OpenAIRE

    Mackay, Tom G.; Lakhtakia, Akhlesh

    2004-01-01

    Mediums which do not support the propagation of plane waves with negative phase velocity (NPV) when viewed at rest can support NPV propagation when they are viewed in a reference frame which is uniformly translated at sufficiently high velocity. Thus, relativistic negative refraction may be exploited in astronomical scenarios.

  9. 世界优秀女子100m栏运动员的速度特征研究%Speed feature of world excellent women 100 -meter hurdle race athletes

    Institute of Scientific and Technical Information of China (English)

    孙婷婷; 黄贝君; 董广新

    2011-01-01

    The paper analyses the competition result index of the world excellent women 100 - meter hurdle race athletes re leased by the IAAF and the biomechanics statistic of this item in the Berlin Track and Field Championship and get the speed utilization rate,%对国际田联公布的世界优秀女子100m栏运动员的比赛成绩参数及柏林田径世锦赛该项目的生物力学数据进行了分析与研究,得出了该项目世界优秀运动员速度利用率、速度保持率、跨栏技术、栏间节奏等方面的参数。这些参数对于了解世界优秀跨栏运动员的速度特征、提高中国运动员的竞技水平提供了参考依据。

  10. Physics of negative absolute temperatures

    Science.gov (United States)

    Abraham, Eitan; Penrose, Oliver

    2017-01-01

    Negative absolute temperatures were introduced into experimental physics by Purcell and Pound, who successfully applied this concept to nuclear spins; nevertheless, the concept has proved controversial: a recent article aroused considerable interest by its claim, based on a classical entropy formula (the "volume entropy") due to Gibbs, that negative temperatures violated basic principles of statistical thermodynamics. Here we give a thermodynamic analysis that confirms the negative-temperature interpretation of the Purcell-Pound experiments. We also examine the principal arguments that have been advanced against the negative temperature concept; we find that these arguments are not logically compelling, and moreover that the underlying "volume" entropy formula leads to predictions inconsistent with existing experimental results on nuclear spins. We conclude that, despite the counterarguments, negative absolute temperatures make good theoretical sense and did occur in the experiments designed to produce them.

  11. Negative Attitudes, Network and Education

    DEFF Research Database (Denmark)

    Bennett, Patrick; la Cour, Lisbeth; Larsen, Birthe

    to an ambiguous impact. Empirically, we consider immigrants’ high school attendance. On the macro-level, we confirm a signficant negative correlation between negative attitudes towards immigrants and high school attendance and a positive impact of networking on high school attendance. On the individual level, we...... use Danish register data to find a signficant positive correlation between negative attitudes towards immigrants and high school attendance and find a positive impact of networking on high school attendance. In both the macro and the micro-econometric analysis we run the same regressions for natives......We consider the impact of negative attitudes against immigrants and immigration on educational choice in a search and wage bargaining model including networking. We consider two cases in terms of the importance of negative attitudes againts immigrants for high and low educated individuals and find...

  12. Analysis of Negative Correlation Learning

    Institute of Scientific and Technical Information of China (English)

    Liu Yong; Zou Xiu-fen

    2003-01-01

    This paper describes negative correlation learning for designing neural network ensembles. Negative correlation learning has been firstly analysed in terms of minimising mutual information on a regression task. By ninimising the mutual information between variables extracted by two neural networks, they are forced to convey different information about some features of their input. Based on the decision boundaries and correct response sets, negative correlation learning has been further studied on two pattern classification problems. The purpose of examining the decision boundaries and the correct response sets is not only to illustrate the learning behavior of negative correlation learning, but also to cast light on how to design more effective neural network ensembles. The experimental results showed the decision boundary of the trained neural network ensemble by negative correlation learning is almost as good as the optimum decision boundary.

  13. Isotropic Negative Thermal Expansion Metamaterials.

    Science.gov (United States)

    Wu, Lingling; Li, Bo; Zhou, Ji

    2016-07-13

    Negative thermal expansion materials are important and desirable in science and engineering applications. However, natural materials with isotropic negative thermal expansion are rare and usually unsatisfied in performance. Here, we propose a novel method to achieve two- and three-dimensional negative thermal expansion metamaterials via antichiral structures. The two-dimensional metamaterial is constructed with unit cells that combine bimaterial strips and antichiral structures, while the three-dimensional metamaterial is fabricated by a multimaterial 3D printing process. Both experimental and simulation results display isotropic negative thermal expansion property of the samples. The effective coefficient of negative thermal expansion of the proposed models is demonstrated to be dependent on the difference between the thermal expansion coefficient of the component materials, as well as on the circular node radius and the ligament length in the antichiral structures. The measured value of the linear negative thermal expansion coefficient of the three-dimensional sample is among the largest achieved in experiments to date. Our findings provide an easy and practical approach to obtaining materials with tunable negative thermal expansion on any scale.

  14. Negative Attitudes, Network and Education

    DEFF Research Database (Denmark)

    Bennett, Patrick; la Cour, Lisbeth; Larsen, Birthe

    , the impact of negative attitudes and networking taking into account that these parameters may influence high and uneducated workers as well as immigrants and natives differently, creating different incentives to acquire education for the two ethnic groups. Using rich Danish administrative data, this paper......This paper explores potential explanations behind the educational gap between young natives and immigrants using two measures, negative attitudes towards immigrants and networking, which may influence natives and immigrants differently. The paper considers, both theoretically and empirically...... finds evidence that greater negative attitudes increase incentives for males to acquire education and that networking also increases immigrant education....

  15. Cognitive representation of negative numbers.

    Science.gov (United States)

    Fischer, Martin H

    2003-05-01

    To understand negative numbers, must we refer to positive number representations (the phylogenetic hypothesis), or do we acquire a negative mental number line (the ontogenetic hypothesis)? In the experiment reported here, participants made lateralized button responses to indicate the larger of two digits from the range -9 to 9. Digit pairs were displayed spatially congruent or incongruent with either a phylogenetic or an ontogenetic mental number line. The pattern of decision latencies suggests that negative numbers become associated with left space, thus supporting the ontogenetic view.

  16. Negative Attitudes, Network and Education

    DEFF Research Database (Denmark)

    Bennett, Patrick; la Cour, Lisbeth; Larsen, Birthe;

    This paper explores potential explanations behind the educational gap between young natives and immigrants using two measures, negative attitudes towards immigrants and networking, which may influence natives and immigrants differently. The paper considers, both theoretically and empirically......, the impact of negative attitudes and networking taking into account that these parameters may influence high and uneducated workers as well as immigrants and natives differently, creating different incentives to acquire education for the two ethnic groups. Using rich Danish administrative data, this paper...... finds evidence that greater negative attitudes increase incentives for males to acquire education and that networking also increases immigrant education....

  17. Adjective metaphors evoke negative meanings.

    Science.gov (United States)

    Sakamoto, Maki; Utsumi, Akira

    2014-01-01

    Previous metaphor studies have paid much attention to nominal metaphors and predicative metaphors, but little attention has been given to adjective metaphors. Although some studies have focused on adjective metaphors, they only examined differences in the acceptability of various types of adjective metaphors. This paper explores the cognitive effects evoked by adjective metaphors. Three psychological experiments revealed that (1) adjective metaphors, especially those modified by color adjectives, tend to evoke negative effect; (2) although the meanings of metaphors are basically affected by the meanings of their vehicles, when a vehicle has a neutral meaning, negative meanings are evoked most frequently for adjective metaphors compared to nominal and predicative metaphors; (3) negative meanings evoked by adjective metaphors are related to poeticness, and poetic metaphors evoke negative meanings more easily than less poetic metaphors. Our research sheds new light on studies of the use of metaphor, which is one of the most basic human cognitive abilities.

  18. Metamaterials and Negative Refractive Index

    National Research Council Canada - National Science Library

    D. R. Smith; J. B. Pendry; M. C. K. Wiltshire

    2004-01-01

    .... Artificial magnetism and negative refractive index are two specific types of behavior that have been demonstrated over the past few years, illustrating the new physics and new applications possible...

  19. Negative numbers in simple arithmetic.

    Science.gov (United States)

    Das, Runa; LeFevre, Jo-Anne; Penner-Wilger, Marcie

    2010-10-01

    Are negative numbers processed differently from positive numbers in arithmetic problems? In two experiments, adults (N = 66) solved standard addition and subtraction problems such as 3 + 4 and 7 - 4 and recasted versions that included explicit negative signs-that is, 3 - (-4), 7 + (-4), and (-4) + 7. Solution times on the recasted problems were slower than those on standard problems, but the effect was much larger for addition than subtraction. The negative sign may prime subtraction in both kinds of recasted problem. Problem size effects were the same or smaller in recasted than in standard problems, suggesting that the recasted formats did not interfere with mental calculation. These results suggest that the underlying conceptual structure of the problem (i.e., addition vs. subtraction) is more important for solution processes than the presence of negative numbers.

  20. Piezoelectric enhancement under negative pressure

    Science.gov (United States)

    Kvasov, Alexander; McGilly, Leo J.; Wang, Jin; Shi, Zhiyong; Sandu, Cosmin S.; Sluka, Tomas; Tagantsev, Alexander K.; Setter, Nava

    2016-07-01

    Enhancement of ferroelectric properties, both spontaneous polarization and Curie temperature under negative pressure had been predicted in the past from first principles and recently confirmed experimentally. In contrast, piezoelectric properties are expected to increase by positive pressure, through polarization rotation. Here we investigate the piezoelectric response of the classical PbTiO3, Pb(Zr,Ti)O3 and BaTiO3 perovskite ferroelectrics under negative pressure from first principles and find significant enhancement. Piezoelectric response is then tested experimentally on free-standing PbTiO3 and Pb(Zr,Ti)O3 nanowires under self-sustained negative pressure, confirming the theoretical prediction. Numerical simulations verify that negative pressure in nanowires is the origin of the enhanced electromechanical properties. The results may be useful in the development of highly performing piezoelectrics, including lead-free ones.

  1. Personality, Negativity, and Political Participation

    Directory of Open Access Journals (Sweden)

    Aaron C. Weinschenk

    2014-08-01

    Full Text Available Scholars have recently started to integrate personality traits into models of political participation. In this paper, we present the results of a survey experiment (N = 724 designed to test whether negative political messages differentially impact people with different personality traits. We found evidence that individuals with high scores on agreeableness were less likely, and individuals with high scores on extraversion were more likely, to report intending to participate in politics than their counterparts after being exposed to negative political messages. Agreeableness and extraversion also interacted with negative messages to influence specific intentions to make a political donation, attend a meeting, rally, or event, and volunteer for a political campaign. We also found suggestive evidence that agreeableness interacted with negativity to influence turnout intentions. The results of this study have important implications for the study of political engagement, the ways in which people interact with political information, and the practice of democratic politics.

  2. Negative magnetic relaxation in superconductors

    Directory of Open Access Journals (Sweden)

    Krasnoperov E.P.

    2013-01-01

    Full Text Available It was observed that the trapped magnetic moment of HTS tablets or annuli increases in time (negative relaxation if they are not completely magnetized by a pulsed magnetic field. It is shown, in the framework of the Bean critical-state model, that the radial temperature gradient appearing in tablets or annuli during a pulsed field magnetization can explain the negative magnetic relaxation in the superconductor.

  3. Use of Negation in Search

    Science.gov (United States)

    2010-06-01

    number of individuals indicated that negation was valuable for them in their shopping on Craigslist and eBay , particularly for collectible items...research or in a quest for rare collectibles on eBay , is sufficient cause for further investigation into the notion of negation in search. Research...that use of advanced search syntax is correlated with users being online for more time, “spend[ing] less time querying and traversing search trails” (p

  4. Negative effects of positive reinforcement

    OpenAIRE

    Perone, Michael

    2003-01-01

    Procedures classified as positive reinforcement are generally regarded as more desirable than those classified as aversive—those that involve negative reinforcement or punishment. This is a crude test of the desirability of a procedure to change or maintain behavior. The problems can be identified on the basis of theory, experimental analysis, and consideration of practical cases. Theoretically, the distinction between positive and negative reinforcement has proven difficult (some would say t...

  5. Negative refraction in photonic crystals

    OpenAIRE

    Baba, T.; Matsumoto, T.; Asatsuma, T.

    2008-01-01

    Photonic crystals are multidimensional periodic gratings, in which the light propagation is dominated by Bragg diffraction that appears to be refraction at the flat surfaces of the crystals. The refraction angle from positive to negative, perfectly or only partially obeying Snell’s law, can be tailored based on photonic band theory. Negative refraction enables novel prism, collimation, and lens effects. Because photonic crystals usually consist of two transparent media, these effects occur at...

  6. Aplicação do modelo binomial na formação de preço de títulos de dívida corporativa no Brasil.

    Directory of Open Access Journals (Sweden)

    José Roberto Securato

    2008-06-01

    Full Text Available Este artigo consiste em uma aplicação do modelo binomial na formação de preços de títulos de dívida e seus componentes – call, conversibilidade, subordinação, senioridade – para uma empresa brasileira. O principal objetivo do trabalho é a adaptação do modelo à realidade brasileira. Os resultados obtidos consistem em estimativas dos preços dos títulos de dívida e da empresa em estudo e comparações com os preços de mercado, procurando identificar oportunidades de compra ou venda desses ativos. Dos seis títulos estudados, três deles apresentaram preços acima do valor de mercado, indicando que o mercado estaria subavaliando o preço desses títulos, enquanto dois outros títulos obtiveram preços abaixo do mercado e um dos títulos praticamente igualou-se ao preço de mercado. O modelo apresentado e suas adaptações indicam a possibilidade de sua aplicação na formação de preço de contratos incompletos avaliando cada uma de suas contingências. Palavras-chave: modelo binominal; avaliação de dívidas; opções reais. Abstract This article presents the implementation of binomial option pricing model to evaluate corporate debt instruments and its components such as call options, convertibility options, seniority and subordination to a Brazilian company. The major results consist of debt securities valuation and its comparison to secondary market prices in order to identify investments opportunities. The paper evaluated six debt securities which have secondary market prices and three of them presented prices above market, two of them were bellow market price and one of them had the same price of the market. The presented model and its adjustments to Brazilian market allow evaluating corporate debt securities and its components, evaluating the impact of new debt issues in the existing ones and comparing debt model and book values. Keywords: binomial model; corporate debt; debt components.

  7. Hurdling over sex? Sport, science, and equity.

    Science.gov (United States)

    Ha, Nathan Q; Dworkin, Shari L; Martínez-Patiño, María José; Rogol, Alan D; Rosario, Vernon; Sánchez, Francisco J; Wrynn, Alison; Vilain, Eric

    2014-08-01

    Between 1968 and 1999, the International Olympic Committee (IOC) required all female athletes to undergo genetic testing as part of its sex verification policy, under the assumption that it needed to prevent men from impersonating women and competing in female-only events. After critics convinced officials that genetic testing was scientifically and ethically flawed for this purpose, the IOC replaced the policy in 1999 with a system allowing for medical evaluations of an athlete's sex only in cases of "reasonable suspicion," but this system also created injustice for athletes and stoked international controversies. In 2011, the IOC adopted a new policy on female hyperandrogenism, which established an upper hormonal limit for athletes eligible to compete in women's sporting events. This new policy, however, still leaves important medical and ethical issues unaddressed. We review the history of sex verification policies and make specific recommendations on ways to improve justice for athletes within the bounds of the current hyperandrogenism policy, including suggestions to clarify the purpose of the policy, to ensure privacy and confidentiality, to gain informed consent, to promote psychological health, and to deploy equitable administration and eligibility standards for male and female athletes.

  8. Humans in space the psychological hurdles

    CERN Document Server

    Kanas, Nick

    2015-01-01

    Using anecdotal reports from astronauts and cosmonauts, and the results from studies conducted in space analog environments on Earth and in the actual space environment, this book broadly reviews the various psychosocial issues that affect space travelers.  Unlike other books that are more technical in format, this text is targeted for the general public.  With the advent of space tourism and the increasing involvement of private enterprise in space, there is now a need to explore the impact of space missions on the human psyche and on the interpersonal relationships of the crewmembers. Separate chapters of the book deal with psychosocial stressors in space and in space analog environments; psychological, psychiatric, interpersonal, and cultural issues pertaining to space missions; positive growth-enhancing aspects of space travel; the crew-ground interaction; space tourism; countermeasures for dealing with space; and unique aspects of a trip to Mars, the outer solar system, and interstellar travel. .

  9. Overcoming Hurdles Implementing Multi-skilling Policies

    Science.gov (United States)

    2015-03-26

    Johnson Chair Dr. K. L. Schultz Member iv AFIT-ENS-MS-15-M-124 Abstract Ogden ALC at Hill AFB has been authorized to promote wage...demonstration project (108th Congress, 2003). The NDAA authorized the Naval Aviation Depots to promote workers certified in multiple trades at the...to achieve the optimal solution based on the mix of jobs and machines, but it does give a target. The shortest processing time (SPT) first rule

  10. Major Hurdles for the Evolution of Sociality.

    Science.gov (United States)

    Korb, Judith; Heinze, Jürgen

    2016-01-01

    Why do most animals live solitarily, while complex social life is restricted to a few cooperatively breeding vertebrates and social insects? Here, we synthesize concepts and theories in social evolution and discuss its underlying ecological causes. Social evolution can be partitioned into (a) formation of stable social groups, (b) evolution of helping, and (c) transition to a new evolutionary level. Stable social groups rarely evolve due to competition over food and/or reproduction. Food competition is overcome in social insects with central-place foraging or bonanza-type food resources, whereas competition over reproduction commonly occurs because staying individuals are rarely sterile. Hence, the evolution of helping is shaped by direct and indirect fitness options and helping is only altruism if it reduces the helper's direct fitness. The helper's capability to gain direct fitness also creates within-colony conflict. This prevents transition to a new evolutionary level.

  11. Defining the Critical Hurdles in Cancer Immunotherapy

    OpenAIRE

    Fox, Bernard A.; Schendel, Dolores J.; Butterfield, Lisa H.; Aamdal, Steinar; Allison, James P.; Ascierto, Paolo Antonio; Atkins, Michael B.; Bartunkova, Jirina; Bergmann, Lothar; Berinstein, Neil; Bonorino, Cristina C; Borden, Ernest; Bramson, Jonathan L; Britten, Cedrik M.; Cao, Xuetao

    2011-01-01

    Scientific discoveries that provide strong evidence of antitumor effects in preclinical models often encounter significant delays before being tested in patients with cancer. While some of these delays have a scientific basis, others do not. We need to do better. Innovative strategies need to move into early stage clinical trials as quickly as it is safe, and if successful, these therapies should efficiently obtain regulatory approval and widespread clinical application. In late 2009 and 2010...

  12. Defining the Critical Hurdles in Cancer Immunotherapy

    OpenAIRE

    Fox, Bernard A.; Schendel, Dolores J.; Butterfield, Lisa H.; Aamdal, Steinar; Allison, James P.; Ascierto, Paolo; Atkins, Michael B.; Bartunkova, Jirina; Bergmann, Lothar; Berinstein, Neil; Bonorino, Cristina C; Borden, Ernest; Bramson, Jonathan L; Britten, Cedrik M.; Cao, Xuetao

    2011-01-01

    Abstract Scientific discoveries that provide strong evidence of antitumor effects in preclinical models often encounter significant delays before being tested in patients with cancer. While some of these delays have a scientific basis, others do not. We need to do better. Innovative strategies need to move into early stage clinical trials as quickly as it is safe, and if successful, these therapies should efficiently obtain regulatory approval and widespread cli...

  13. Defining the critical hurdles in cancer immunotherapy

    OpenAIRE

    Fox, Bernard A.; Schendel, Dolores J.; Butterfield, Lisa H.; Aamdal, Steinar; Allison, James P.; Ascierto, Paolo Antonio; Atkins, Michael B.; Bartunkova, Jirina; Bergmann, Lothar; Berinstein, Neil; Bonorino, Cristina C; Borden, Ernest; Bramson, Jonathan L; Britten, Cedrik M.; Cao, Xuetao

    2011-01-01

    Scientific discoveries that provide strong evidence of antitumor effects in preclinical models often encounter significant delays before being tested in patients with cancer. While some of these delays have a scientific basis, others do not. We need to do better. Innovative strategies need to move into early stage clinical trials as quickly as it is safe, and if successful, these therapies should efficiently obtain regulatory approval and widespread clinical application. In late 2009 and 2010...

  14. Defining the critical hurdles in cancer immunotherapy

    OpenAIRE

    Fox Bernard A; Schendel Dolores J; Butterfield Lisa H; Aamdal Steinar; Allison James P; Ascierto Paolo; Atkins Michael B; Bartunkova Jirina; Bergmann Lothar; Berinstein Neil; Bonorino Cristina C; Borden Ernest; Bramson Jonathan L; Britten Cedrik M; Cao Xuetao

    2011-01-01

    Abstract Scientific discoveries that provide strong evidence of antitumor effects in preclinical models often encounter significant delays before being tested in patients with cancer. While some of these delays have a scientific basis, others do not. We need to do better. Innovative strategies need to move into early stage clinical trials as quickly as it is safe, and if successful, these therapies should efficiently obtain regulatory approval and widespread clinical application. In late 2009...

  15. Modelling marine protected areas: insights and hurdles

    OpenAIRE

    Elizabeth A Fulton; Bax, Nicholas J.; Bustamante, Rodrigo H.; Jeffrey M. Dambacher; Dichmont, Catherine; Dunstan, Piers K.; Hayes, Keith R.; Hobday, Alistair J.; Pitcher, Roland; Plagányi, Éva E.; Punt, André E; Savina-rolland, Marie; Anthony D M Smith; David C. Smith

    2015-01-01

    Models provide useful insights into conservation and resource management issues and solutions. Their use to date has highlighted conditions under which no-take marine protected areas (MPAs) may help us to achieve the goals of ecosystem-based management by reducing pressures, and where they might fail to achieve desired goals. For example, static reserve designs are unlikely to achieve desired objectives when applied to mobile species or when compromised by climate-related ecosystem restructur...

  16. Modelling marine protected areas: insights and hurdles.

    Science.gov (United States)

    Fulton, Elizabeth A; Bax, Nicholas J; Bustamante, Rodrigo H; Dambacher, Jeffrey M; Dichmont, Catherine; Dunstan, Piers K; Hayes, Keith R; Hobday, Alistair J; Pitcher, Roland; Plagányi, Éva E; Punt, André E; Savina-Rolland, Marie; Smith, Anthony D M; Smith, David C

    2015-11-05

    Models provide useful insights into conservation and resource management issues and solutions. Their use to date has highlighted conditions under which no-take marine protected areas (MPAs) may help us to achieve the goals of ecosystem-based management by reducing pressures, and where they might fail to achieve desired goals. For example, static reserve designs are unlikely to achieve desired objectives when applied to mobile species or when compromised by climate-related ecosystem restructuring and range shifts. Modelling tools allow planners to explore a range of options, such as basing MPAs on the presence of dynamic oceanic features, and to evaluate the potential future impacts of alternative interventions compared with 'no-action' counterfactuals, under a range of environmental and development scenarios. The modelling environment allows the analyst to test if indicators and management strategies are robust to uncertainties in how the ecosystem (and the broader human-ecosystem combination) operates, including the direct and indirect ecological effects of protection. Moreover, modelling results can be presented at multiple spatial and temporal scales, and relative to ecological, economic and social objectives. This helps to reveal potential 'surprises', such as regime shifts, trophic cascades and bottlenecks in human responses. Using illustrative examples, this paper briefly covers the history of the use of simulation models for evaluating MPA options, and discusses their utility and limitations for informing protected area management in the marine realm. © 2015 The Author(s).

  17. Oil and gas supply : hurdles and opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Giusti, L. [Centre for Strategic and International Studies, Washington, DC (United States)

    2006-07-01

    The socioeconomic development in Latin America was discussed with reference to its abundant and diverse resources. Despite its large population, Latin America represents only 6 per cent of the world gross domestic product (GDP) and a less than 6 per cent of the total world trading. This presentation described the problems of large deficits, poor economic policies, large debt and corruption that provoked inflation, economic slowdown, and foreign debt in Latin America. Policy makers agreed that reforms were needed if Latin American economies were to grow more than 6 per cent a year, and to lower the number of people living in poverty in the region. The second-generation reform for Latin America was meant to promote economic development without inflation. It is based on quality public sector governance; fiscal strengthening; an enhanced legal and regulatory framework; efficient financial markets; and, labour and market reform. This presentation also discussed the oil and gas industry's contention with the perceptions that the economic crisis in Latin America was caused by globalization, international trade and acquisitive industrialized countries. An initiative was launched in 1994 to build an integrated energy data bank, evaluate existing interconnections among Latin American countries, and identify barriers for a larger integration to facilitate and improve commercial activities. It was emphasized that while the United States has a large deficit of oil, Canada and Latin America have large surpluses of energy resources, which if developed efficiently and effectively, can be a leading engine of regional development and an important contributor to global competitiveness. Canada is the largest supplier of energy, including oil, natural gas and electricity to the United States, the world's largest energy consumer and largest oil and gas market. Mexico and Brazil were identified as the other 2 large economies in the region's energy chain, but Mexico is self sufficient and Brazil has a modest dependency. The important players on the supply side include Mexico, Brazil, Venezuela and Trinidad/Tobago. Also, Colombia is a player with its excellent exploration and production model, its stability and institutional strength. It was suggested that Bolivia could become an important player if changes take place to promote the development of its huge natural gas resources.

  18. Genetic privacy in sports: clearing the hurdles.

    Science.gov (United States)

    Callier, Shawneequa

    2012-12-01

    As genomic medicine continues to advance and inform clinical care, knowledge gained is likely to influence sports medicine and training practices. Susceptibility to injury, sudden cardiac failure, and other serious conditions may one day be tackled on a subclinical level through genetic testing programs. In addition, athletes may increasingly consider using genetic testing services to maximize their performance potential. This paper assesses the role of privacy and genetic discrimination laws that would apply to athletes who engage in genetic testing and the limits of these protections.

  19. Hurdles Ahead for Zika Vaccine: Experts

    Science.gov (United States)

    ... in the state. NIAID has developed an experimental DNA-based vaccine that recently entered human safety trials. At the ... make sure you give it a good ethical review before you challenge a human," ... that a candidate vaccine is available in quantities for testing, which is ...

  20. GIS in oceanography: Status, hurdles and prospects

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.

    stream_size 5 stream_content_type text/plain stream_name Remote_Sens_GIS_Environ_Plan_1995_575.pdf.txt stream_source_info Remote_Sens_GIS_Environ_Plan_1995_575.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset...

  1. Aplicação do modelo binomial na formação de preço de títulos de dívida corporativa no Brasil.

    Directory of Open Access Journals (Sweden)

    José Roberto Securato

    2008-05-01

    components such as call options, convertibility options, seniority and subordination to a Brazilian company. The major results consist of debt securities valuation and its comparison to secondary market prices in order to identify investments opportunities. The paper evaluated six debt securities which have secondary market prices and three of them presented prices above market, two of them were bellow market price and one of them had the same price of the market. The presented model and its adjustments to Brazilian market allow evaluating corporate debt securities and its components, evaluating the impact of new debt issues in the existing ones and comparing debt model and book values. Keywords: binomial model; corporate debt; debt components.

  2. Formas de razonamientos que muestran estudiantes de maestría de matemática educativa sobre las distribuciones uniforme discreta y binomial mediante problemas de simulación en Fathom

    OpenAIRE

    Ramírez, Greivin

    2009-01-01

    Según Garfield, et al ([3, pág. 300,]), uno de los prerrequisitos que deben tener los estudiantes antes de estudiar las distribuciones muestrales, siendo estas la piedra angular de la inferencia estadística ([16, pág. 277,], [3, pág. 295,]), es la idea de distribución: describir distribuciones de datos (como la uniforme y la binomial), caracterizar su forma, centro, dispersión y variabilidad (es el corazón de la estadística según [11], [12], [4], [5], [15]). Así, esta investigación responde a...

  3. 私募股权投资中二叉树期权估值模型研究%Research on the Binomial Tree Option Valuation Model in Private Equity Investment

    Institute of Scientific and Technical Information of China (English)

    李爱民; 韩佳佳

    2016-01-01

    In this paper, real option theory is applied to make investment decision of private equity, we analyze the defects of tradition-al valuation methods and the option characteristics of private equity investment, besides, we construct the option valuation model of binomial tree under risk neutral condition and carry on empirical analysis with the new investment decision model.%本文将实物期权理论引入私募股权投资决策中,分析了传统估值方法存在的缺陷及私募股权投资的期权特性,构建了基于风险中性条件的二叉树期权估值模型,并对该模型在私募股权投资中进行了实例分析。

  4. Factores determinantes de la utilización de instrumentos públicos para la gestión del riesgo en la industria vitivinícola chilena: un modelo logit binomial

    Directory of Open Access Journals (Sweden)

    Germán Lobos

    2008-12-01

    Full Text Available The main objective of this research was to identify the determining factors of the use of public instruments to manage risk in the Chilean wine industry. A binomial logistic regression model was proposed. Based on a survey of 104 viticulture and winemaking companies, a database was constructed between January and October 2007. The model was fitted using maximum likelihood estimation. The variables that turned out to be statistically significant were: risk of the wine price, availability of external consultancy and number of permanent workers. From the Public Management point of view, the main conclusion suggests that the use of public instruments could be increased if viticulturists and winemakers had more external counseling.

  5. 二项索赔下保费收取为Poisson过程的破产概率研究%Research on Ruin Probability of Insurance Charge with Poisson Process Under Binomial Claim

    Institute of Scientific and Technical Information of China (English)

    王治强; 刘冬元

    2013-01-01

    In this paper,we extended the classical risk model to a discrete risk model in which the premium rate was a Poisson process and the number of compensation rate was a binomial process. It discussed the nature of surplus process,gave a theorem about the ruin probability and several inferences.%将经典风险模型推广为保费收取为Poisson过程,赔偿次数为二项过程的离散风险模型,讨论了盈余过程的性质,给出了关于破产概率的一个定理和几个推论。

  6. Talk About Approximate Calculation for Binomial Distribution and Application in Insurance%谈二项分布的近似计算及其在保险问题中的应用

    Institute of Scientific and Technical Information of China (English)

    张艳

    2012-01-01

    Poisson theorem, Di mo eph - Laplace theorem provide us with an approximate calculation formula for the binomial distribution. In this paper, the conditions to adopt the theorem are studied and the two approximate calculation formula are used to calculate the insurance problems.%泊松定理、棣莫弗-拉普拉斯定理给出了二项分布的近似计算公式,拟对定理中的应用条件进‘行整理研究,并通过实例,将这两种近似计算公式分别应用于保险问题的计算中。

  7. Input calibration for negative originals

    Science.gov (United States)

    Tuijn, Chris

    1995-04-01

    One of the major challenges in the prepress environment consists of controlling the electronic color reproduction process such that a perfect match of any original can be realized. Whether this goal can be reached depends on many factors such as the dynamic range of the input device (scanner, camera), the color gamut of the output device (dye sublimation printer, ink-jet printer, offset), the color management software etc. The characterization of the color behavior of the peripheral devices is therefore very important. Photographs and positive transparents reflect the original scene pretty well; for negative originals, however, there is no obvious link to either the original scene or a particular print of the negative under consideration. In this paper, we establish a method to scan negatives and to convert the scanned data to a calibrated RGB space, which is known colorimetrically. This method is based on the reconstruction of the original exposure conditions (i.e., original scene) which generated the negative. Since the characteristics of negative film are quite diverse, a special calibration is required for each combination of scanner and film type.

  8. A non-linear beta-binomial regression model for mapping EORTC QLQ- C30 to the EQ-5D-3L in lung cancer patients: a comparison with existing approaches.

    Science.gov (United States)

    Khan, Iftekhar; Morris, Stephen

    2014-11-12

    The performance of the Beta Binomial (BB) model is compared with several existing models for mapping the EORTC QLQ-C30 (QLQ-C30) on to the EQ-5D-3L using data from lung cancer trials. Data from 2 separate non small cell lung cancer clinical trials (TOPICAL and SOCCAR) are used to develop and validate the BB model. Comparisons with Linear, TOBIT, Quantile, Quadratic and CLAD models are carried out. The mean prediction error, R(2), proportion predicted outside the valid range, clinical interpretation of coefficients, model fit and estimation of Quality Adjusted Life Years (QALY) are reported and compared. Monte-Carlo simulation is also used. The Beta-Binomial regression model performed 'best' among all models. For TOPICAL and SOCCAR trials, respectively, residual mean square error (RMSE) was 0.09 and 0.11; R(2) was 0.75 and 0.71; observed vs. predicted means were 0.612 vs. 0.608 and 0.750 vs. 0.749. Mean difference in QALY's (observed vs. predicted) were 0.051 vs. 0.053 and 0.164 vs. 0.162 for TOPICAL and SOCCAR respectively. Models tested on independent data show simulated 95% confidence from the BB model containing the observed mean more often (77% and 59% for TOPICAL and SOCCAR respectively) compared to the other models. All algorithms over-predict at poorer health states but the BB model was relatively better, particularly for the SOCCAR data. The BB model may offer superior predictive properties amongst mapping algorithms considered and may be more useful when predicting EQ-5D-3L at poorer health states. We recommend the algorithm derived from the TOPICAL data due to better predictive properties and less uncertainty.

  9. The negation bias: When negations signal stereotypic expectancies

    NARCIS (Netherlands)

    Beukeboom, C.J.; Finkenauer, C.; Wigboldus, D.H.J.

    2010-01-01

    Research on linguistic biases shows that stereotypic expectancies are implicitly reflected in language and are thereby subtly communicated to message recipients. We examined whether these findings extend to the use of negations (e.g., not smart instead of stupid). We hypothesized that people use mor

  10. Dose from slow negative muons.

    Science.gov (United States)

    Siiskonen, T

    2008-01-01

    Conversion coefficients from fluence to ambient dose equivalent, from fluence to maximum dose equivalent and quality factors for slow negative muons are examined in detail. Negative muons, when stopped, produce energetic photons, electrons and a variety of high-LET particles. Contribution from each particle type to the dose equivalent is calculated. The results show that for the high-LET particles the details of energy spectra and decay yields are important for accurate dose estimates. For slow negative muons the ambient dose equivalent does not always yield a conservative estimate for the protection quantities. Especially, the skin equivalent dose is strongly underestimated if the radiation-weighting factor of unity for slow muons is used. Comparisons to earlier studies are presented.

  11. Chinese Negative Transfer in Translation

    Institute of Scientific and Technical Information of China (English)

    王红琴

    2009-01-01

    The nat ive language can help learn a foreign language, but foreign language learners const ant ly suffer negat ivet ransfer from t heir mot her language. We,as Chinese English learners in t he environment ,in t he English-Chinese t ranslat ion inChinese is oft en negat ive impact .The present paper probes int o t he essence of language t ransfer ,making a det ailed comparisonbet ween Chinese and English vocabulary in t erms of concept ual meaning,connot at ive meaning and idioms in order t o find out t hebasic principle of t ranslat ion which may help avoid negat ive t ransfer from Chinese.

  12. Negative-Pressure Pulmonary Edema.

    Science.gov (United States)

    Bhattacharya, Mallar; Kallet, Richard H; Ware, Lorraine B; Matthay, Michael A

    2016-10-01

    Negative-pressure pulmonary edema (NPPE) or postobstructive pulmonary edema is a well-described cause of acute respiratory failure that occurs after intense inspiratory effort against an obstructed airway, usually from upper airway infection, tumor, or laryngospasm. Patients with NPPE generate very negative airway pressures, which augment transvascular fluid filtration and precipitate interstitial and alveolar edema. Pulmonary edema fluid collected from most patients with NPPE has a low protein concentration, suggesting hydrostatic forces as the primary mechanism for the pathogenesis of NPPE. Supportive care should be directed at relieving the upper airway obstruction by endotracheal intubation or cricothyroidotomy, institution of lung-protective positive-pressure ventilation, and diuresis unless the patient is in shock. Resolution of the pulmonary edema is usually rapid, in part because alveolar fluid clearance mechanisms are intact. In this review, we discuss the clinical presentation, pathophysiology, and management of negative-pressure or postobstructive pulmonary edema.

  13. Sigma Models with Negative Curvature

    CERN Document Server

    Alonso, Rodrigo; Manohar, Aneesh V.

    2016-01-01

    We construct Higgs Effective Field Theory (HEFT) based on the scalar manifold H^n, which is a hyperbolic space of constant negative curvature. The Lagrangian has a non-compact O(n,1) global symmetry group, but it gives a unitary theory as long as only a compact subgroup of the global symmetry is gauged. Whether the HEFT manifold has positive or negative curvature can be tested by measuring the S-parameter, and the cross sections for longitudinal gauge boson and Higgs boson scattering, since the curvature (including its sign) determines deviations from Standard Model values.

  14. Negative refractive index in chiral metamaterials.

    Science.gov (United States)

    Zhang, Shuang; Park, Yong-Shik; Li, Jensen; Lu, Xinchao; Zhang, Weili; Zhang, Xiang

    2009-01-16

    We experimentally demonstrate a chiral metamaterial exhibiting negative refractive index at terahertz frequencies. The presence of strong chirality in the terahertz metamaterial lifts the degeneracy for the two circularly polarized waves and allows for the achievement of negative refractive index without requiring simultaneously negative permittivity and negative permeability. The realization of terahertz chiral negative index metamaterials offers opportunities for investigation of their novel electromagnetic properties, such as negative refraction and negative reflection, as well as important terahertz device applications.

  15. Photonic crystal negative refractive optics.

    Science.gov (United States)

    Baba, Toshihiko; Abe, Hiroshi; Asatsuma, Tomohiko; Matsumoto, Takashi

    2010-03-01

    Photonic crystals (PCs) are multi-dimensional periodic gratings, in which the light propagation is dominated by Bragg diffraction that appears to be refraction at the flat surfaces of the PC. The refraction angle from positive to negative, perfectly or only partially obeying Snell's law, can be tailored using photonic band theory. The negative refraction enables novel prism, collimation, and lens effects. Because PCs usually consist of two transparent media, these effects occur at absorption-free frequencies, affording significant design flexibility for free-space optics. The PC slab, a high-index membrane with a two-dimensional airhole array, must be carefully designed to avoid reflection and diffraction losses. Light focusing based on negative refraction forms a parallel image of a light source, facilitating optical couplers and condenser lenses for wavelength demultiplexing. A compact wavelength demultiplexer can be designed by combining the prism and lens effects. The collimation effect is obtainable not only inside but also outside of the PC by optimizing negative refractive condition.

  16. Symmetric relations of finite negativity

    NARCIS (Netherlands)

    Kaltenbaeck, M.; Winkler, H.; Woracek, H.; Forster, KH; Jonas, P; Langer, H

    2006-01-01

    We construct and investigate a space which is related to a symmetric linear relation S of finite negativity on an almost Pontryagin space. This space is the indefinite generalization of the completion of dom S with respect to (S.,.) for a strictly positive S on a Hilbert space.

  17. Questioning Zero and Negative Numbers

    Science.gov (United States)

    Wilcox, Virginia B.

    2008-01-01

    After experiencing a Developing Mathematical Ideas (DMI) class on the construction of algebraic concepts surrounding zero and negative numbers, the author conducted an interview with a first grader to determine the youngster's existing level of understanding about these topics. Uncovering young students' existing understanding can provide focus…

  18. Incisional Negative Pressure Wound Therapy

    DEFF Research Database (Denmark)

    Hyldig, Nana

    Women with a pre-gestational body mass index (BMI) above 30 kg/m2 giving birth by caesarean section are at high risk of surgical wound infection compared with women with a BMI below 30 kg/m2. Incisional Negative Pressure Wound Therapy (iNPWT) is one strategy to reduce the rate of surgical wound...

  19. A Semantic Analysis of Negative Concord

    NARCIS (Netherlands)

    Wouden van der, Ton; Zwarts, Frans

    1993-01-01

    It is not uncommon in natural languages that negation seems to behave in an illogical manner. The general term for the many cases where multiple occurrences of morphologically negative constituents express a single semantic negation is negative concord (Labov 1979). Negative concord may take either

  20. Hurdle technology to preserve the 'Golden' papaya post harvest quality;Metodos combinados para preservar a qualidade pos-colheita do mamao 'Golden' tipo exportacao

    Energy Technology Data Exchange (ETDEWEB)

    Molinari, Andrea Cristina Fialho, E-mail: molinari_af@yahoo.co

    2007-07-01

    significant differences among papayas submitted to different treatments. A synergism was verified on the techniques combination, with the best results obtained from the association of CP + PEabs + gamma-irradiation at 0.4 kGy, which reached a total storage period of 35 days. Thus, that is the post harvest hurdle technology recommend for exporting 'Golden' papayas to markets with quarantine restrictions to fruit-flies (author)