bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impoundment of the Zipingpu reservoir and triggering of the 2008 Mw 7.9 Wenchuan earthquake, China
Authors: Tao Wei , Masterlark Timothy , Shen Zheng‐Kang , Ronchin Erika 
Published: September 2015

AbstractImpoundment of the Zipingpu reservoir (ZR), China, began in September 2005 and was followed 2.7 years later by the 2008 Mw 7.9 Wenchuan earthquake (WE) rupturing the Longmen Shan Fault (LSF), with its epicenter ~12 km away from the ZR. Based on the poroelastic theory, we employ three‐dimensional finite element models to simulate the evolution of stress and pore pressure due to reservoir impoundment, and its effect on the Coulomb failure stress on the LSF. The results indicate that the reservoir impoundment formed a pore pressure front that slowly propagated through the crust with fluid diffusion. The reservoir loading induced either moderate or no increase of the Coulomb failure stress at the hypocenter prior to the WE. The Coulomb failure stress, however, grew ~9.3–69.1 kPa in the depth range of 1–8 km on the LSF, which may have advanced tectonic loading of the fault system by ~60–450 years. Due to uncertainties of fault geometry and hypocenter location of the WE, it is inconclusive whether impoundment of the ZR directly triggered the WE. However, a small event at the hypocenter could have triggered large rupture elsewhere on fault, where the asperities were weakened by the ZR. The microseismicity around the ZR also showed an expanding pattern from the ZR since its impoundment, likely associated with diffusion of a positive pore pressure pulse. These results suggest a poroelastic triggering effect (even if indirectly) of the WE due to the impoundment of the ZR.
The Iquique earthquake sequence of April 2014: Bayesian modeling accounting for prediction uncertainty
Authors: Duputel Z. , Jiang J. , Jolivet R. , Simons M. , Rivera L. , Ampuero J.‐P. , Riel B. , Owen S. E. , Moore A. W. , Samsonov S. V. , Ortega Culaciati F. , Minson S. E. 
Published: September 2015

AbstractThe subduction zone in northern Chile is a well‐identified seismic gap that last ruptured in 1877. On 1 April 2014, this region was struck by a large earthquake following a two week long series of foreshocks. This study combines a wide range of observations, including geodetic, tsunami, and seismic data, to produce a reliable kinematic slip model of the Mw=8.1 main shock and a static slip model of the Mw=7.7 aftershock. We use a novel Bayesian modeling approach that accounts for uncertainty in the Green's functions, both static and dynamic, while avoiding nonphysical regularization. The results reveal a sharp slip zone, more compact than previously thought, located downdip of the foreshock sequence and updip of high‐frequency sources inferred by back‐projection analysis. Both the main shock and the Mw=7.7 aftershock did not rupture to the trench and left most of the seismic gap unbroken, leaving the possibility of a future large earthquake in the region.
MESSENGER observations of the dayside low‐latitude boundary layer in Mercury's magnetosphere
Authors: Liljeblad Elisabet , Karlsson Tomas , Raines Jim M. , Slavin James A. , Kullen Anita , Sundberg T. , Zurbuchen Thomas H. 
Published: September 2015

AbstractObservations from MErcury Surface Space ENvironment GEochemistry, and Ranging (MESSENGER)'s Magnetometer and Fast Imaging Plasma Spectrometer instruments during the first orbital year have resulted in the identification of 25 magnetopause crossings in Mercury's magnetosphere with significant low‐latitude boundary layers (LLBLs). Of these crossings 72% are observed dawnside and 65% for northward interplanetary magnetic field. The estimated LLBL thickness is 450 ± 56 km and increases with distance to noon. The Na+ group ion is sporadically present in 14 of the boundary layers, with an observed average number density of 22 ± 11% of the proton density. Furthermore, the average Na+ group gyroradii in the layers is 220 ± 34 km, the same order of magnitude as the LLBL thickness. Magnetic shear, plasma β and reconnection rates have been estimated for the LLBL crossings and compared to those of a control group (non‐LLBL) of 61 distinct magnetopause crossings which show signs of nearly no plasma inside the magnetopause. The results indicate that reconnection is significantly slower, or even suppressed, for the LLBL crossings compared to the non‐LLBL cases. Possible processes that form or impact the LLBL are discussed. Protons injected through the cusp or flank may be important for the formation of the LLBL. Furthermore, the opposite asymmetry in the Kelvin‐Helmholtz instability (KHI) as compared to the LLBL rules out the KHI as a dominant formation mechanism. However, the KHI and LLBL could be related to each other, either by the impact of sodium ions gyrating across the magnetopause or by the LLBL preventing the growth of KH waves on the dawnside.
Evolution of the Current Population Survey
Authors: Wolter Kirk M. , Polivka Anne E. , Lubich Antoinette 
Published: September 2015

AbstractThe Current Population Survey (CPS) is one of the world's foremost and historic household surveys, providing the data to generate the United State's monthly unemployment rate along with a myriad of other key labor‐force statistics. This paper discusses the evolution of the CPS from its origin in the 1940s. In addition to documenting current procedures, the paper highlights important changes in concepts, survey questions, sample designs, estimation procedures, and data collection procedures. The paper addresses how official estimates derived from the data are released to the public, and briefly discusses the organizational structure that has supported the CPS throughout its history.
Newsboy Inventory Problem
Authors: Berk Emre , Gürler Ülkü 
Published: September 2015

AbstractA definition and classical formulation of the newsboy inventory model as a profit maximization problem is provided. The structure of the optimal stocking policy is given. Alternative formulations of mean‐variance, down‐side risk,VaR(value‐at‐risk), andCVaR(conditional value‐at‐risk) for general demand distributions and aminimaxformulation for the distribution‐free newsboy model are also presented. Demand estimation in the presence of fully observable and censored sales is discussed from the frequentist and Bayesian perspectives. Explicit formulas are provided for Bayesian updating of a comprehensive set of demand functions.
EmpiricalBayes
Authors: Datta Somnath 
Published: September 2015

AbstractThe empirical Bayes technique has been proved to be immensely useful in various applications of statistics. We have covered the basic theoretical developments of two forms of this technique, parametric and nonparametric, and explored its connection to the compound decision problem and shrinkage estimation. Recent applications to differential gene expression analysis and false discovery rate control are discussed.
Epidemiological Statistics – Further Issues
Authors: McNeil Don 
Published: September 2015

AbstractEpidemiological studies use statistical methods to understand the factors that cause, reduce, and prevent diseases in human populations. These studies estimate the parameters in a target population based on representative samples, and can be qualitative or quantitative, descriptive or comparative, and observational or experimental. Parameters of interest include levels of disease and associations between risk factors and disease outcomes. Concept maps are useful for showing causal paths between risk factors, disease outcomes, and intervening variables (confounders) that could distort the association. The statistical methods can be classified by the type and role of the data, and are subject to both inaccuracy or lack of statistical power (due to sampling variability) and bias (due to faulty measurement, differential selection of subjects, or confounding). Matching of subjects can improve accuracy. Mantel–Haenszel methods can reduce confounding bias. Meta‐analysis is used to combine results from different studies. Statistical models include linear, logistic, and Poisson regression and the proportional hazards model for handling censored data.
Categorical Data, Marginal Models for
Authors: Molenberghs Geert 
Published: September 2015

AbstractWe briefly review two building blocks (generalized linear models and linear mixed models) for models for repeated categorical data. Three families of models for repeated categorical data are introduced: marginal models, conditional models, and random‐effects models. A number of marginal models are presented for binary and ordinal data in turn. Major differences between marginal models and conditional models (such as loglinear models) are discussed. Attention is given to nonlikelihood‐based methods, such as generalized estimating equations and pseudo‐likelihood. We discuss marginal models that are derived from random‐effects specifications as well and place some emphasis on how to allow for overdispersion.
Copula Process,
A
rchimedean
Authors: Malov Sergey V. 
Published: September 2015

Abstract
Archimedean copulas have a wide range of applications in probability theory and in mathematical statistics. A copula arose first in the work of Sklar in 1959. It is the function that characterizes principal connection of components in a random vector independently of marginal distributions. Archimedean copula process was introduced as a generalization of the scheme of independent random variables. The most of interesting applications of this object was in the order statistics theory and in the extreme values theory. The extreme type theorems and some characterizations of classes of sequences via properties of order statistics and record values can be improved from the class of independent random variables to the class of Archimedean copula processes. In this way, the proportional Archimedean copula process appeared as the generalization of the ‐scheme for independent random variables. Some representations of the Archimedean copula process via independent random variables as well as MTP positive dependence property are also given.
Saddlepoint Approximations
Authors: Gatto Riccardo 
Published: September 2015

AbstractThe saddlepoint method provides accurate approximations for the distributions of many test statistics, and estimators, as well as for important probabilities arising in various stochastic models. The saddlepoint approximation is a large deviations technique which is substantially more accurate than limiting normal or Edgeworth approximations, especially in the presence of very small sample sizes or very small probabilities. The outstanding accuracy of the saddlepoint approximation can be explained by the fact that it has bounded relative error.
Wear Processes
Authors: Griffith William S. 
Published: September 2015

AbstractThere is an extensive literature on a class of deterioration models in reliability theory calledwear processes. These can be used as models of time to failure in which a stochastic process describes the wear that a device accrues over time until it ultimately fails. This article provides a brief survey and can direct the interested reader to papers that have developed the work in this field.
Power Law Process
Authors: Rigdon Steven E. 
Published: September 2015

AbstractThe power law process is a nonhomegeoeous Poisson process whose intensity function is proportional to a power of timet. It is often used to model the event times for recurrent events, such as the failure times of repairable systems. We consider the problems of inference for the power law process and extend this to the case of multiple realizations of the power law process, which would occur, for example, if we were modeling several similar repairable systems. Both Bayesian and classical approaches are described. Finally, several extensions of the power law process to more general models are suggested.
Environmental Toxicology, Statistics in
Authors: Zhang Jing , Bailer A. John , Oris James T. 
Published: September 2015

AbstractEnvironmental toxicity refers to the impact of a hazard or stressor at one or more levels of biological organization. This impact can range from molecular and cellular levels to whole organism, population, ecosystem, or landscape levels. The statistical methods employed to examine these impacts will reflect the level of organization and the measurements taken at this level. The methods associated with this spectrum are described and illustrated in this article.
Convergence and Mixing inMarkov ChainMonteCarlo: Advanced Algorithms and Latest Developments
Authors: Peluso Stefano , Mira Antonietta 
Published: September 2015

AbstractWe survey possible strategies to improve the performance of Markov chain Monte Carlo methods either by reducing the asymptotic variance of the resulting estimators or by increasing the speed of convergence to stationarity. Recent advances in the direction of the pseudomarginal approach, Gradient‐based algorithms, and Approximate Bayesian Computation are also highlighted.
Effect Modification
Authors: McKnight Barbara 
Published: September 2015

Abstract

Effect modification occurs when a measure of the association between an explanatory variable and an outcome variable is modified, or differs, over different values of a third variable, called the
effect modifier
. For a given measure of association between explanatory variable and outcome variable , there is usually a corresponding regression model scale on which the presence of effect modification corresponds to the presence of statistical interaction between and the effect modifier . This correspondence is described for several additive and multiplicative measures of association.
Educational Psychology: Measuring Change over Time
Authors: Kulikowich Jonna M. 
Published: September 2015

AbstractEducational psychologists study changes over time that reflect academic, cognitive, emotional, and social development of students. The purpose of this article is to review the basic principles and procedures of the statistical applications used by educational psychologists to study change. While repeated measuresANOVAis widely used in empirical studies published recently in refereed journals, researchers are as likely to use growth‐curve modeling or structural equation modeling to test their hypotheses. Both growth‐curve modeling and structural equation modeling afford educational psychologists advantages in the analysis of change that overcome limitations of repeated measuresANOVA. A brief description of each statistical technique is provided with a summary of how the procedure has been applied by educational psychologists. Testing of assumptions, estimating effect sizes and power, and current statistical advances in the study of how individuals' affect, behavior, and cognition change are discussed.
Regression Trees
Authors: LeBlanc Michael 
Published: September 2015

AbstractRegression trees are a flexible statistical method for modeling the conditional distribution of a response variable given a vector of predictors or covariates. Trees have several advantages compared with classical parametric regression methods: they are nonparametric; they include powerful variable subset selection; they are robust to outliers in the covariate space; and they are used easily on a wide variety of data structures. Importantly, the tree algorithm has also been widely utilized as a component of more complex prediction algorithms that involve combining or ensembles of trees.
Methodology of Adaptive Randomization
Authors: Buyse Marc E. 
Published: September 2015

AbstractSimple randomization consists of allocating treatments to patients with equal probability. Attempts to improve over simple randomization stem from the desire (i) to ensure that a prespecified number of patients is enrolled in each treatment arm, (ii) to ensure balance with respect to important baseline prognostic factors across all treatment arms, or (iii) to favor (i.e., allocate with higher probability) the treatment arm that is currently faring better. These objectives can be fulfilled, respectively, by use of treatment‐adaptive randomization, covariate‐adaptive randomization, and outcome‐adaptive randomization. Treatment‐adaptive randomization can be implemented as a restricted randomization through randomly permuted blocks or as a dynamic method using a biased coin. Similarly, covariate‐adaptive randomization can use randomly permuted blocks within strata or minimization. Outcome‐adaptive randomization remains controversial because of it produces only modest gains in terms of total number of failures at the cost of increased complexity, a risk of accrual bias, and the potential for ethical concerns.
Stochastic Search Variable Selection (SSVS)
Authors: Perrakis Konstantinos , Ntzoufras Ioannis 
Published: September 2015

AbstractThe stochastic search variable selection (SSVS), introduced by George and McCulloch[1], is one of the prominent Bayesian variable selection approaches for regression problems. Some of the basic principles of modern Bayesian variable selection methods were first introduced via the SSVS algorithm such as the use of a vector of variable inclusion indicators. SSVS can effectively search large model spaces, identifying the maximum a posteriori and median probability models, and also readily produce Bayesian model averaging estimates. A number of generalizations and extensions of the method have appeared in the statistical literature implementing SSVS to a variety of applications such as generalized linear models, contingency tables, time series data, and factor analysis.
Learning from Instructor‐managed and Self‐managed Split‐attention Materials
Authors: Gordon Chloe , Tindall‐Ford Sharon , Agostinho Shirley , Paas Fred 
Published: September 2015

SummaryInstructor‐managed physical integration of mutually dependent, but spatially separated materials, is an effective way to overcome negative effects of split‐attention on learning. This study examined whether teaching students to self‐manage split‐attention materials would be effective for learning. Seventy‐eight primary‐school students learned about the water cycle, either by studying split‐attention examples, integrated examples or self‐managed split‐attention examples. It was hypothesised that students who study instructor‐integrated materials and students who study self‐integrated materials would outperform students who study split‐attention materials. The results showed that students learned more from instructor‐integrated materials than from split‐attention materials, thereby confirming the split‐attention effect. The implications for future research on self‐management are discussed.Copyright © 2015 John Wiley & Sons, Ltd.
Unusually Large Young’s Moduli of Amino Acid Molecular Crystals
Authors: Azuri Ido , Meirzadeh Elena , Ehre David , Cohen Sidney R. , Rappe Andrew M. , Lahav Meir , Lubomirsky Igor , Kronik Leeor 
Published: September 2015

AbstractYoung’s moduli of selected amino acid molecular crystals were studied both experimentally and computationally using nanoindentation and dispersion‐corrected density functional theory. The Young modulus is found to be strongly facet‐dependent, with some facets exhibiting exceptionally high values (as large as 44 GPa). The magnitude of Young’s modulus is strongly correlated with the relative orientation between the underlying hydrogen‐bonding network and the measured facet. Furthermore, we show computationally that the Young modulus can be as large as 70–90 GPa if facets perpendicular to the primary direction of the hydrogen‐bonding network can be stabilized. This value is remarkably high for a molecular solid and suggests the design of hydrogen‐bond networks as a route for rational design of ultra‐stiff molecular solids.
1‐Alkynyltriazenes as Functional Analogues of Ynamides
Authors: Perrin Florian G. , Kiefer Gregor , Jeanbourquin Loïc , Racine Sophie , Perrotta Daniele , Waser Jérôme , Scopelliti Rosario , Severin Kay 
Published: September 2015

AbstractThe chemical reactivity of 1‐alkynyltriazenes has been investigated and is found to parallel the reactivity of ynamides. The similarity in reactivity of these two classes of compounds is demonstrated by addition reactions with acids, by cycloaddition reactions with ketenes, tetracyanoethene, and cyclopropanes, as well as by intramolecular cyclization reactions. The presence of reactive triazene groups in the products enables subsequent transformations. Overall, our results suggest that 1‐alkynyltriazenes should become valuable reagents in synthetic organic chemistry.
Polypyrrole–vinyl aniline modified cyclohexanone formaldehyde resin copolymers: a comparative study of the resin preparation
Authors: Ateş Güvel Esin , Kızılcan Nilgün 
Published: September 2015

ABSTRACTIn this study, the synthesis of polypyrrole‐b‐vinyl aniline modified cyclohexanone formaldehyde resin (PPy‐b‐CFVAnR) block copolymers by a combination of condensation polymerization and chemical oxidative polymerization processes was examined. First, a cyclohexanone formaldehyde resin containing vinyl aniline units [4‐ vinyl aniline modified cyclşohexanone formaldehyde resin (CFVAnR)] was prepared by a direct condensation reaction of 4‐vinyl aniline and cyclohexanone with formaldehyde in an in situ modification reaction. CFVAnR and pyrrole (Py) were then used with a conventional method of in situ chemical oxidative polymerization. The reactions were carried out with heat‐activated potassium persulfate salt in the presence of p‐toluene sulfonic acid in a dimethyl sulfoxide–water binary solvent system; this led to the formation of desired block copolymers. The effects of the oxidant–monomer molar ratio, dopant existence, addition order of the reactants, and reaction temperature on the yield, conductivity, and morphology of the resulting products were investigated. PPy‐b‐CFVAnR copolymers prepared with a resin‐to‐Py molar ratio of 1:40 showed conductivity in the range 3.7 × 10−1 to 3.8 × 10−2 S/cm. Oxidant‐to‐Py molar ratios of 0.5 and 1.0 were proposed to be the optimum stoichiometries for higher conductivity and yield, respectively, of the copolymer. The morphology of the copolymer (PPy‐b‐CFVAnR) was investigated with environmental scanning electron microscopy analyses. The results indicate that the surface of the copolymer was composed of well‐distributed nanospheres with average particle diameters of 60–85 nm. Also, the synthesized PPy‐b‐CFVAnR had a higher thermal stability than the pure CFVAnR. The chemical composition and structure of the PPy‐b‐CFVAnR copolymers were characterized by Fourier transform infrared spectroscopy and measurement. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 132, 42841.
Observer‐Based Consensus Tracking for Nonlinear Multi‐Agent Systems With Intermittent Communications
Authors: Chu Hongjun , Gao Lixin , Zhang Weidong , Ou Linlin 
Published: September 2015

AbstractThis paper addresses the observer‐based consensus tracking problem of multi‐agent systems with intermittent communications. The agent dynamics are modeled as general linear systems with Lipschitz nonlinearity. Under the assumption that each agent can intermittently share its relative output with neighbors, a class of an observer‐type protocol is proposed, and the consensus tracking problem can be converted further into the stability problem of the nonlinear switching systems. Using a combined tool from M matrix theory, switching theory and the averaging approach, a multi‐step algorithm is presented to construct the observer gains and protocol parameters, and the sufficient criteria established not only can ensure the state estimates convergence to the real values but also can guarantee the follower states synchronize to those of the leader. The obtained results reveal the relationships among the communication rate, the convergence rate, and the dwell time of switching topologies. Finally, the theoretical findings are validated by a numerical example.