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2015

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Articles 1321 - 1350 of 12617

Full-Text Articles in Physical Sciences and Mathematics

Bayesian Analysis Under Progressively Censored Rayleigh Data, Gyan Prakash Nov 2015

Bayesian Analysis Under Progressively Censored Rayleigh Data, Gyan Prakash

Journal of Modern Applied Statistical Methods

The one-parameter Rayleigh model is considered as an underlying model for evaluating the properties of Bayes estimator under Progressive Type-II right censored data. The One‑Sample Bayes prediction bound length (OSBPBL) is also measured. Based on two different asymmetric loss functions a comparative study presented for Bayes estimation. A simulation study was used to evaluate their comparative properties.


An Empirical Study On Different Ranking Methods For Effective Data Classification, Ilangovan Sangaiah, A. Vincent Antony Kumar, Appavu Balamurugan Nov 2015

An Empirical Study On Different Ranking Methods For Effective Data Classification, Ilangovan Sangaiah, A. Vincent Antony Kumar, Appavu Balamurugan

Journal of Modern Applied Statistical Methods

Ranking is the attribute selection technique used in the pre-processing phase to emphasize the most relevant attributes which allow models of classification simpler and easy to understand. It is a very important and a central task for information retrieval, such as web search engines, recommendation systems, and advertisement systems. A comparison between eight ranking methods was conducted. Ten different learning algorithms (NaiveBayes, J48, SMO, JRIP, Decision table, RandomForest, Multilayerperceptron, Kstar) were used to test the accuracy. The ranking methods with different supervised learning algorithms give different results for balanced accuracy. It was shown the selection of ranking methods could be …


Two Stage Robust Ridge Method In A Linear Regression Model, Adewale Folaranmi Lukman, Oyedeji Isola Osowole, Kayode Ayinde Nov 2015

Two Stage Robust Ridge Method In A Linear Regression Model, Adewale Folaranmi Lukman, Oyedeji Isola Osowole, Kayode Ayinde

Journal of Modern Applied Statistical Methods

Two Stage Robust Ridge Estimators based on robust estimators M, MM, S, LTS are examined in the presence of autocorrelation, multicollinearity and outliers as alternative to Ordinary Least Square Estimator (OLS). The estimator based on S estimator performs better. Mean square error was used as a criterion for examining the performances of these estimators.


Semi-Parametric Non-Proportional Hazard Model With Time Varying Covariate, Kazeem A. Adeleke, Alfred A. Abiodun, R. A. Ipinyomi Nov 2015

Semi-Parametric Non-Proportional Hazard Model With Time Varying Covariate, Kazeem A. Adeleke, Alfred A. Abiodun, R. A. Ipinyomi

Journal of Modern Applied Statistical Methods

The application of survival analysis has extended the importance of statistical methods for time to event data that incorporate time dependent covariates. The Cox proportional hazards model is one such method that is widely used. An extension of the Cox model with time-dependent covariates was adopted when proportionality assumption are violated. The purpose of this study is to validate the model assumption when hazard rate varies with time. This approach is applied to model data on duration of infertility subject to time varying covariate. Validity is assessed by a set of simulation experiments and results indicate that a non proportional …


Structural Properties Of Transmuted Weibull Distribution, Kaisar Ahmad, S. P. Ahmad, A. Ahmed Nov 2015

Structural Properties Of Transmuted Weibull Distribution, Kaisar Ahmad, S. P. Ahmad, A. Ahmed

Journal of Modern Applied Statistical Methods

The transmuted Weibull distribution, and a related special case, is introduced. Estimates of parameters are obtained by using a new method of moments.


New Entropy Estimators With Smaller Root Mean Squared Error, Amer Ibrahim Al-Omari Nov 2015

New Entropy Estimators With Smaller Root Mean Squared Error, Amer Ibrahim Al-Omari

Journal of Modern Applied Statistical Methods

New estimators of entropy of continuous random variable are suggested. The proposed estimators are investigated under simple random sampling (SRS), ranked set sampling (RSS), and double ranked set sampling (DRSS) methods. The estimators are compared with Vasicek (1976) and Al-Omari (2014) entropy estimators theoretically and by simulation in terms of the root mean squared error (RMSE) and bias values. The results indicate that the suggested estimators have less RMSE and bias values than their competing estimators introduced by Vasicek (1976) and Al-Omari (2014).


Caution For Software Use Of New Statistical Methods (R), Akiva J. Lorenz, Barry S. Markman, Shlomo Sawilowsky Nov 2015

Caution For Software Use Of New Statistical Methods (R), Akiva J. Lorenz, Barry S. Markman, Shlomo Sawilowsky

Journal of Modern Applied Statistical Methods

Open source programming languages such as R allow statisticians to develop and rapidly disseminate advanced procedures, but sometimes at the expense of a proper vetting process. A new example is the least trimmed squares regression available in R’s lqs() in the MASS library. It produces pretty regression lines, particularly in the presence of outliers. However, this procedure lacks a defined standard error, and thus it should be avoided.


Inferences About The Skipped Correlation Coefficient: Dealing With Heteroscedasticity And Non-Normality, Rand Wilcox Nov 2015

Inferences About The Skipped Correlation Coefficient: Dealing With Heteroscedasticity And Non-Normality, Rand Wilcox

Journal of Modern Applied Statistical Methods

A common goal is testing the hypothesis that Pearson’s correlation is zero and typically this is done based on Student’s T test. There are, however, several well-known concerns. First, Student’s T is sensitive to heteroscedasticity. That is, when it rejects, it is reasonable to conclude that there is dependence, but in terms of making a decision about the strength of the association, it is unsatisfactory. Second, Pearson’s correlation is not robust: it can poorly reflect the strength of the association. Even a single outlier can have a tremendous impact on the usual estimate of Pearson’s correlation, which can result in …


In (Partial) Defense Of .05, Thomas R. Knapp Nov 2015

In (Partial) Defense Of .05, Thomas R. Knapp

Journal of Modern Applied Statistical Methods

Researchers are frequently chided for choosing the .05 alpha level as the determiner of statistical significance (or non-significance). A partial justification is provided.


The Distribution Of The Inverse Square Root Transformed Error Component Of The Multiplicative Time Series Model, Bright F. Ajibade, Chinwe R. Nwosu, J. I. Mbegdu Nov 2015

The Distribution Of The Inverse Square Root Transformed Error Component Of The Multiplicative Time Series Model, Bright F. Ajibade, Chinwe R. Nwosu, J. I. Mbegdu

Journal of Modern Applied Statistical Methods

The probability density function, mean and variance of the inverse square-root transformed left-truncated N(1,σ2) error component e*t(=1/ √et) of the multiplicative time series model were established. A comparison of key-statistical properties of e*t and et confirmed normality with mean 1 but with Var(e*t) ≈1/4Var(et) when σ≤0.14. Hence σ≤0.14 is the required condition for successful transformation.


Front Matter, Jmasm Editors Nov 2015

Front Matter, Jmasm Editors

Journal of Modern Applied Statistical Methods

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Comment On Faa Rule Revision - Transport Category Aircraft, Paul F. Eschenfelder, Valter Battistoni Nov 2015

Comment On Faa Rule Revision - Transport Category Aircraft, Paul F. Eschenfelder, Valter Battistoni

Paul F. Eschenfelder

No abstract provided.


Candels Visual Classifications: Scheme, Data Release, And First Results, Jeyhan S. Kartaltepe, Mark Mozena, Dale D. Kocevski, Daniel H. Mcintosh, Jennifer Lotz, Eric F. Bell, Sandra M. Faber, Harry C. Ferguson, David C. Koo, Robert Bassett, Maksym Bernyk, Kirsten Blancato, Frederic Bournaud, Paolo Cassata, M. Castellano, Edmond Cheung, Christopher J. Conselice, D. Croton, Tomas Dahlen, Duilia F. De Mello, Laura Degroot, Jennifer Donley, Javiera Guedes, Norman A. Grogin, Nimish Hathi, Matt Hilton, Brett Hollon, Anton M. Koekemoer, Nick Liu, Ray A. Lucas Nov 2015

Candels Visual Classifications: Scheme, Data Release, And First Results, Jeyhan S. Kartaltepe, Mark Mozena, Dale D. Kocevski, Daniel H. Mcintosh, Jennifer Lotz, Eric F. Bell, Sandra M. Faber, Harry C. Ferguson, David C. Koo, Robert Bassett, Maksym Bernyk, Kirsten Blancato, Frederic Bournaud, Paolo Cassata, M. Castellano, Edmond Cheung, Christopher J. Conselice, D. Croton, Tomas Dahlen, Duilia F. De Mello, Laura Degroot, Jennifer Donley, Javiera Guedes, Norman A. Grogin, Nimish Hathi, Matt Hilton, Brett Hollon, Anton M. Koekemoer, Nick Liu, Ray A. Lucas

Physics and Astronomy Faculty Publications

We have undertaken an ambitious program to visually classify all galaxies in the five CANDELS fields down to H < 24.5 involving the dedicated efforts of over 65 individual classifiers. Once completed, we expect to have detailed morphological classifications for over 50,000 galaxies spanning 0 < z < 4 over all the fields, with classifications from 3 to 5 independent classifiers for each galaxy. Here, we present our detailed visual classification scheme, which was designed to cover a wide range of CANDELS science goals. This scheme includes the basic Hubble sequence types, but also includes a detailed look at mergers and interactions, the clumpiness of galaxies, k-corrections, and a variety of other structural properties. In this paper, we focus on the first field to be completed—GOODS-S, which has been classified at various depths. The wide area coverage spanning the full field (wide+deep+ERS) includes 7634 galaxies that have been classified by at least three different people. In the deep area of the field, 2534 galaxies have been classified by at least five different people at three different depths. With this paper, we release to the public …


From Equations To Tri-Quations And Multi-Quations, Mourat Tchoshanov, Olga Kosheleva, Vladik Kreinovich Nov 2015

From Equations To Tri-Quations And Multi-Quations, Mourat Tchoshanov, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

In general, an equation A(x1, ..., xn)= B(x1, ..., xn) corresponds to the situation when we have two quantities A(x1, ..., xn) and B(x1, ..., xn) which are known to be equal, we know how each of these quantities depends on the unknown parameters x1, ..., xn, and we want to find the values of the unknowns xi from this equality -- and from other similar equalities. In some practical situations, instead of two equal values, we have three …


Why The Graph Isomorphism Problem Is Easier Than Propositional Satisfiability: A Possible Qualitative Explanation, Vladik Kreinovich, Olga Kosheleva Nov 2015

Why The Graph Isomorphism Problem Is Easier Than Propositional Satisfiability: A Possible Qualitative Explanation, Vladik Kreinovich, Olga Kosheleva

Departmental Technical Reports (CS)

A recent result has shown that the graph isomorphism problem can be solved in quasi-polynomial time, while the general belief is that only exponential time algorithms are possible for propositional satisfiability. This is somewhat counter-intuitive, since for propositional satisfiability, we need to look for one of 2n options, while in graph isomorphism, we need to look for one of n! options, and n! is much larger than 2n. Our qualitative explanation for this counter-intuitive fact comes from the fact that, in general, a graph isomorphism problem has a unique solution -- in contrast to propositional satisfiability which, …


Decision Making Under Interval (And More General) Uncertainty: Monetary Vs. Utility Approaches, Vladik Kreinovich Nov 2015

Decision Making Under Interval (And More General) Uncertainty: Monetary Vs. Utility Approaches, Vladik Kreinovich

Departmental Technical Reports (CS)

In many situations, e.g., in financial and economic decision making, the decision results either in a money gain (or loss) and/or in the gain of goods that can be exchanged for money or for other goods. In such situations, interval uncertainty means that we do not know the exact amount of money that we will get for each possible decision, we only know lower and upper bounds on this amount. In this case, a natural idea is to assign a fair price to different alternatives, and then to use these fair prices to select the best alternative. In the talk, …


Science Is Helpful For Engineering Applications: A Theoretical Explanation Of An Empirical Observation, Olga Kosheleva, Vladik Kreinovich Nov 2015

Science Is Helpful For Engineering Applications: A Theoretical Explanation Of An Empirical Observation, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

Empirical evidence shows that when engineering design uses scientific analysis, we usually get a much better performance that for the system designed by using a trial-and-error engineering approach. In this paper, we provide a quantitative explanation for this empirical observation.


Why The Range Of A Robust Statistic Under Interval Uncertainty Is Often Easier To Compute, Olga Kosheleva, Vladik Kreinovich Nov 2015

Why The Range Of A Robust Statistic Under Interval Uncertainty Is Often Easier To Compute, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

In statistical analysis, we usually use the observed sample values x1, ..., xn to compute the values of several statistics v(x1, ..., xn) -- such as sample mean, sample variance, etc. The usual formulas for these statistics implicitly assume that we know the exact values x1, ..., xn. In practice, the sample values X1, ..., Xn come from measurements and are, thus, only approximations to the actual (unknown) values x1, ..., xn of the corresponding quantity. Often, the only information that we have …


X-Ray Emission From The Giant Magnetosphere Of The Magnetic O-Type Star Ngc 1624-2, V. Petit, D. H. Cohen, G. A. Wade, Y. Naze, S. P. Owocki, J. O. Sundqvist, A. Ud-Doula, A. Fullerton, M. Leutenegger, Marc Gagne Nov 2015

X-Ray Emission From The Giant Magnetosphere Of The Magnetic O-Type Star Ngc 1624-2, V. Petit, D. H. Cohen, G. A. Wade, Y. Naze, S. P. Owocki, J. O. Sundqvist, A. Ud-Doula, A. Fullerton, M. Leutenegger, Marc Gagne

Earth & Space Sciences Faculty Publications

No abstract provided.


Mcicsl Newsletter - November 2015, Shannon R. Trimboli Education Coordinator Nov 2015

Mcicsl Newsletter - November 2015, Shannon R. Trimboli Education Coordinator

MCICSL Newsletter

This issue includes the following:

Partners Recognized for Water Quality Research at Mammoth Cave National Park and Increasing Diversity in the Geosciences

Texas A&M – Galveston Students Participate in Citizen Science at Mammoth Cave National Park

Northern Kentucky University and the Mammoth Cave International Center for Science and Learning to Host Partners in the Parks Program at Mammoth Cave National Park

as well as education and research highlights, and MCICSL symposium information


Perceptions Of Tornadoes, Tornado Warnings, Safety Actions, And Risk: Effects On Warning Response Among Undergraduates In Nebraska, Sabrina T. Jauernic Nov 2015

Perceptions Of Tornadoes, Tornado Warnings, Safety Actions, And Risk: Effects On Warning Response Among Undergraduates In Nebraska, Sabrina T. Jauernic

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Few studies show how university students perceive and respond to tornado warnings, or how they gain tornado-related knowledge. Lacking in the literature are investigations of how perceptions of tornado risk may influence actions. Using two separate surveys and two large samples of undergraduates enrolled in the University of Nebraska, the author determined significant relationships between student demographics, perceptions, and response actions. Incorrect perceptions were found, such as overpasses and southwest corners of buildings being safe, and cities being invulnerable to tornadoes. International students, especially, assumed cities were safe from tornadoes. Students had a tendency to confirm their risk instead of …


Revisiting Scalar Glueballs, Hai-Yang Cheng, Chun-Khiang Chua, Keh-Fei Liu Nov 2015

Revisiting Scalar Glueballs, Hai-Yang Cheng, Chun-Khiang Chua, Keh-Fei Liu

Physics and Astronomy Faculty Publications

It is commonly believed that the lowest-lying scalar glueball lies somewhere in the isosinglet scalar mesons f0(1370), f0(1500) and f0(1710) denoted generically by f0. In this work we consider lattice calculations and experimental data to infer the glue and qq components of f0. These include the calculations of the scalar glueball masses in quenched and unquenched lattice QCD, measurements of the radiative decays J/ψγf0, the ratio of f0 decays to ππ, KK and ηη, the ratio of J/ψ decays …


Tungsten Disulphide Based All Fiber Q-Switching Cylindrical-Vector Beam Generation, J. Lin, K. Yan, Yong Zhou, L. X. Xu, C. Gu, Qiwen Zhan Nov 2015

Tungsten Disulphide Based All Fiber Q-Switching Cylindrical-Vector Beam Generation, J. Lin, K. Yan, Yong Zhou, L. X. Xu, C. Gu, Qiwen Zhan

Electro-Optics and Photonics Faculty Publications

We proposed and demonstrated an all fiber passively Q-switching laser to generate cylindrical-vectorbeam, a two dimensional material,tungsten disulphide (WS2), was adopted as a saturable absorber inside the laser cavity, while a few-mode fiber Bragg grating was used as a transverse mode-selective output coupler. The repetition rate of the Q-switching output pulses can be varied from 80 kHz to 120 kHz with a shortest duration of 958 ns. Attributed to the high damage threshold and polarization insensitivity of the WS2 based saturable absorber, the radially polarized beam and azimuthally polarized beam can be easily generated in the Q-switchingfiber laser.


Partial Covariance Based Functional Connectivity Computation Using Ledoit-Wolf Covariance Regularization, Matthew R. Brier, Anish Mitra, John E. Mccarthy, Beau M. Ances, Abraham Z. Snyder Nov 2015

Partial Covariance Based Functional Connectivity Computation Using Ledoit-Wolf Covariance Regularization, Matthew R. Brier, Anish Mitra, John E. Mccarthy, Beau M. Ances, Abraham Z. Snyder

Mathematics Faculty Publications

Highlights •We use the well characterized matrix regularization technique described by Ledoit and Wolf to calculate high dimensional partial correlations in fMRI data. •Using this approach we demonstrate that partial correlations reveal RSN structure suggesting that RSNs are defined by widely and uniquely shared variance. •Partial correlation functional connectivity is sensitive to changes in brain state indicating that they contain functional information. Functional connectivity refers to shared signals among brain regions and is typically assessed in a task free state. Functional connectivity commonly is quantified between signal pairs using Pearson correlation. However, resting-state fMRI is a multivariate process exhibiting a …


So, You Want To 3d Print A Landscape? An Outline Of Some Methods, Dylan J. Mckevitt, Thomas L. Rice, Emily Jackson, Victoria Couser Nov 2015

So, You Want To 3d Print A Landscape? An Outline Of Some Methods, Dylan J. Mckevitt, Thomas L. Rice, Emily Jackson, Victoria Couser

Alumni Book Gallery

No abstract provided.


Population Of 13be In A Nucleon Exchange Reaction, B. R. Marks, P. A. Deyoung, J. K. Smith, T. Baumann, J. Brown, N. Frank, J. Hinnefeld, M. Hoffman, M. D. Jones, Z. Kohley, A. N. Kuchera, B. Luther, A. Spyrou, Sharon L. Stephenson, C. Sullivan, M. Thoennessen, N. Viscariello, S. J. Williams Nov 2015

Population Of 13be In A Nucleon Exchange Reaction, B. R. Marks, P. A. Deyoung, J. K. Smith, T. Baumann, J. Brown, N. Frank, J. Hinnefeld, M. Hoffman, M. D. Jones, Z. Kohley, A. N. Kuchera, B. Luther, A. Spyrou, Sharon L. Stephenson, C. Sullivan, M. Thoennessen, N. Viscariello, S. J. Williams

Physics and Astronomy Faculty Publications

The neutron-unbound nucleus Be13 was populated with a nucleon exchange reaction from a 71 MeV/u secondary B13 beam. The decay-energy spectrum was reconstructed using invariant mass spectroscopy based on Be12 fragments in coincidence with neutrons. The data could be described with an s-wave resonance at Er=0.73(9)MeV with a width of Γr=1.98(34)MeVand a d-wave resonance at Er=2.56(13)MeV with a width of Γr=2.29(73)MeV. The observed spectral shape is consistent with previous one-proton removal reaction measurements from B14.


Particle Transport In Low-Collisionality H-Mode Plasmas On Diii-D, Saskia Mordijck, X. Wang, E. J. Doyle, T. L. Rhodes, Et Al. Nov 2015

Particle Transport In Low-Collisionality H-Mode Plasmas On Diii-D, Saskia Mordijck, X. Wang, E. J. Doyle, T. L. Rhodes, Et Al.

Arts & Sciences Articles

In this paper we show that changing from an ion temperature gradient (ITG) to a trapped electron mode (TEM) dominant turbulence regime (based on linear gyrokinetic simulations) results experimentally in a strong density pump-out (defined as a reduction in line-averaged density) in low collisionality, low power H-mode plasmas. We vary the turbulence drive by changing the heating from predominantly ion heated using neutral beam injection to electron heated using electron cyclotron heating, which changes the T-e/T-i ratio and the temperature gradients. Perturbed gas puff experiments show an increase in transport outside rho = 0.6, through a strong increase in the …


From Subcompact To Domain Representable, William Fleissner, Lynne Yengulalp Nov 2015

From Subcompact To Domain Representable, William Fleissner, Lynne Yengulalp

Mathematics Faculty Publications

No abstract provided.


Inclusive Cross Sections For Pairs Of Identified Light Charged Hadrons And For Single Protons In E^{+}E^{-} At Sqrt[S]=10.58gev, R. Seidl Et Al., D. Joffe Nov 2015

Inclusive Cross Sections For Pairs Of Identified Light Charged Hadrons And For Single Protons In E^{+}E^{-} At Sqrt[S]=10.58gev, R. Seidl Et Al., D. Joffe

Faculty Articles

We report the first double differential cross sections of two charged pions and kaons (e+e−→hhX) in electron-positron annihilation as a function of the fractional energies of the two hadrons for any charge and hadron combination. The dependence of these dihadron cross sections on the topology (same, opposite hemisphere or anywhere) is also studied with the help of the event shape variable thrust and its axis. The ratios of these dihadron cross sections for different charges and hadron combinations directly shed light on the contributing fragmentation functions. For example, we find that the ratio of same-sign pion pairs over opposite-sign pion …


Gaussian Nonlinear Line Attractor For Learning Multidimensional Data, Theus H. Aspiras, Vijayan K. Asari, Wesam Sakla Nov 2015

Gaussian Nonlinear Line Attractor For Learning Multidimensional Data, Theus H. Aspiras, Vijayan K. Asari, Wesam Sakla

Electrical and Computer Engineering Faculty Publications

The human brain’s ability to extract information from multidimensional data modeled by the Nonlinear Line Attractor (NLA), where nodes are connected by polynomial weight sets. Neuron connections in this architecture assumes complete connectivity with all other neurons, thus creating a huge web of connections. We envision that each neuron should be connected to a group of surrounding neurons with weighted connection strengths that reduces with proximity to the neuron. To develop the weighted NLA architecture, we use a Gaussian weighting strategy to model the proximity, which will also reduce the computation times significantly.

Once all data has been trained in …