Critical Assessment Of Outcomes In Acute Aortic Dissection (Type A) At A Community Hospital: A 10 Year Review,
2012
Lehigh Valley Health Network
Critical Assessment Of Outcomes In Acute Aortic Dissection (Type A) At A Community Hospital: A 10 Year Review, Timothy S. Misselbeck, James K. Wu Md, Stephen Deturk Ba, Michael F. Szwerc Md, Sanjay M. Mehta Md, Theodore G. Phillips Md, Gary W. Szydlowski Md, Raymond L. Singer Md
Department of Surgery
No abstract provided.
Factors Associated With Loss To Follow-Up Among Hiv-Infected Patients At An Urban, Hospital-Based Outpatient Hiv Clinic,
2012
Lehigh Valley Health Network
Factors Associated With Loss To Follow-Up Among Hiv-Infected Patients At An Urban, Hospital-Based Outpatient Hiv Clinic, Timothy J. Friel Md, Anthony Nerino, Lynn Nagel, J D'Aversa, Anthony Strobel, Dorothy Faulkner Phd
Department of Medicine
No abstract provided.
Analysis Of Discrete Choice Probit Models With Structured Correlation Matrices,
2012
Old Dominion University
Analysis Of Discrete Choice Probit Models With Structured Correlation Matrices, Bhaskara Ravi
Mathematics & Statistics Theses & Dissertations
Discrete choice models are very popular in Economics and the conditional logit model is the most widely used model to analyze consumer choice behavior, which was introduced in a seminal paper by McFadden (1974). This model is based on the assumption that the unobserved factors, which determine the consumer choices, are independent and follow a Gumbel distribution, widely known as the Independence of irrelevant Alternatives (IIA) assumption. Alternate models that relax IIA assumption are the Generalized Extreme Value (GEV) models, which allow dependency between unobserved factors. However, GEV models do not incorporate all dependency patterns, other choice behaviors such as …
Abel Dynamic Equations Of The First And Second Kind,
2012
Missouri University of Science and Technology
Abel Dynamic Equations Of The First And Second Kind, Sabrina Heike Streipert
Masters Theses
"In this work, we study Abel dynamic equations of the first and the second kind. After a brief introduction to time scales, we introduce the Abel differential equations of the first and the second kind, as well as the canonical Abel form in the continuous case. Using the existing information, we derive novel results for time scales. We provide formulas for the Abel dynamic equations of the second kind and present a solution method. We furthermore achieve a special class of Abel equations of the first kind and discuss the canonical Abel equation. We get relations between common dynamic equations …
Equivalent Circuit Model Of Coaxial Probes For Patch Antennas,
2012
Missouri University of Science and Technology
Equivalent Circuit Model Of Coaxial Probes For Patch Antennas, Y. S. Hu, Yanzhi Zhang, Jun Fan
Mathematics and Statistics Faculty Research & Creative Works
An equivalent circuit model of coaxial probes is derived directly from the intrinsic via circuit model. as all the higher-order evanescent modes have been included analytically in the parasitic circuit elements, only the propagating mode needs to be considered by the simplest uniform-current model of a coaxial probe in numerical solvers such as -nite element method (FEM) or -nite divergence time domain (FDTD). This avoids dense meshes or sub-gridding techniques and greatly reduces the computational efforts for accurate calculation of the probe input impedance. the derived equivalent circuit model and the new feeding technique have been validated by both analytical …
Noise, Bifurcations, And Modeling Of Interacting Particle Systems,
2011
Naval Research Laboratory
Noise, Bifurcations, And Modeling Of Interacting Particle Systems, Luis Mier-Y-Teran-Romero, Eric Forgoston, Ira B. Schwartz
Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works
We consider the stochastic patterns of a system of communicating, or coupled, self-propelled particles in the presence of noise and communication time delay. For sufficiently large environmental noise, there exists a transition between a translating state and a rotating state with stationary center of mass. Time delayed communication creates a bifurcation pattern dependent on the coupling amplitude between particles. Using a mean field model in the large number limit, we show how the complete bifurcation unfolds in the presence of communication delay and coupling amplitude. Relative to the center of mass, the patterns can then be described as transitions between …
Identification And Efficient Estimation Of The Natural Direct Effect Among The Untreated,
2011
University of California, Berkeley, School of Public Health - Division of Biostatistics
Identification And Efficient Estimation Of The Natural Direct Effect Among The Untreated, Samuel D. Lendle, Mark J. Van Der Laan
U.C. Berkeley Division of Biostatistics Working Paper Series
The natural direct effect (NDE), or the effect of an exposure on an outcome if an intermediate variable was set to the level it would have been in the absence of the exposure, is often of interest to investigators. In general, the statistical parameter associated with the NDE is difficult to estimate in the non-parametric model, particularly when the intermediate variable is continuous or high dimensional. In this paper we introduce a new causal parameter called the natural direct effect among the untreated, discus identifiability assumptions, and show that this new parameter is equivalent to the NDE in a randomized …
Flexible Distributed Lag Models Using Random Functions With Application To Estimating Mortality Displacement From Heat-Related Deaths,
2011
Johns Hopkins University
Flexible Distributed Lag Models Using Random Functions With Application To Estimating Mortality Displacement From Heat-Related Deaths, Roger D. Peng
Johns Hopkins University, Dept. of Biostatistics Working Papers
No abstract provided.
Modeling Criminal Careers As Departures From A Unimodal Population Age-Crime Curve: The Case Of Marijuana Use, Donatello Telesca, Elena Erosheva, Derek Kreager, Ross Matsueda
COBRA Preprint Series
A major aim of longitudinal analyses of life course data is to describe the within- and between-individual variability in a behavioral outcome, such as crime. Statistical analyses of such data typically draw on mixture and mixed-effects growth models. In this work, we present a functional analytic point of view and develop an alternative method that models individual crime trajectories as departures from a population age-crime curve. Drawing on empirical and theoretical claims in criminology, we assume a unimodal population age-crime curve and allow individual expected crime trajectories to differ by their levels of offending and patterns of temporal misalignment. We …
Toxicity Profiling Of Engineered Nanomaterials Via Multivariate Dose Response Surface Modeling,
2011
UCLA, Biostatistics
Toxicity Profiling Of Engineered Nanomaterials Via Multivariate Dose Response Surface Modeling, Trina Patel, Donatello Telesca, Saji George, Andre Nel
COBRA Preprint Series
New generation in-vitro high throughput screening (HTS) assays for the assessment of engineered nanomaterials provide an opportunity to learn how these particles interact at the cellular level, particularly in relation to injury pathways. These types of assays are often characterized by small sample sizes, high measurement error and high dimensionality as multiple cytotoxicity outcomes are measured across an array of doses and durations of exposure. In this article we propose a probability model for toxicity profiling of engineered nanomaterials. A hierarchical framework is used to account for the multivariate nature of the data by modeling dependence between outcomes and thereby …
Screening Designs That Minimize Model Dependence,
2011
Brigham Young University - Provo
Screening Designs That Minimize Model Dependence, Kenneth P. Fairchild
Theses and Dissertations
When approaching a new research problem, we often use screening designs to determine which factors are worth exploring in more detail. Before exploring a problem, we don't know which factors are important. When examining a large number of factors, it is likely that only a handful are significant and that even fewer two-factor interactions will be significant. If there are important interactions, it is likely that they are connected with the handful of significant main effects. Since we don't know beforehand which factors are significant, we want to choose a design that gives us the highest probability a priori of …
Spatial Analysis Of Fatal Automobile Crashes In Kentucky,
2011
Western Kentucky University
Spatial Analysis Of Fatal Automobile Crashes In Kentucky, William Nathan Oris
Masters Theses & Specialist Projects
Fatal automobile crashes have claimed the lives of over 33,000 people each year in the United States since 1995. As in any point event, fatal crash events do not occur randomly in time or space. The objectives of this study were to identify spatial patterns and hot spots in FARS (Fatal Analysis Reporting System) fatal crash events based on temporal and demographic characteristics. The methods employed included 1) rate calculation using FARS points and average daily traffic flow; 2) planar kernel density estimation of FARS crash events based on temporal and demographic attributes within the data; and 3) two case …
A General Family Of Dual To Ratio-Cum-Product Estimator In Sample Surveys,
2011
University of New Mexico
A General Family Of Dual To Ratio-Cum-Product Estimator In Sample Surveys, Florentin Smarandache, Rajesh Singh, Mukesh Kumar, Pankaj Chauhan, Nirmala Sawan
Branch Mathematics and Statistics Faculty and Staff Publications
This paper presents a family of dual to ratio-cum-product estimators for the finite population mean. Under simple random sampling without replacement (SRSWOR) scheme, expressions of the bias and mean-squared error (MSE) up to the first order of approximation are derived. We show that the proposed family is more efficient than usual unbiased estimator, ratio estimator, product estimator, Singh estimator (1967), Srivenkataramana (1980) and Bandyopadhyaya estimator (1980) and Singh et al. (2005) estimator. An empirical study is carried out to illustrate the performance of the constructed estimator over others.
Design And Implementation Of An Open Framework For Ubiquitous Carbon Footprint Calculator Applications,
2011
Marquette University
Design And Implementation Of An Open Framework For Ubiquitous Carbon Footprint Calculator Applications, Farzana Rahman, Casey O'Brien, Sheikh Iqbal Ahamed, He Zhang, Lin Liu
Mathematics, Statistics and Computer Science Faculty Research and Publications
As climate change is becoming an important global issue, more and more people are beginning to pay attention to reducing greenhouse gas emissions. To measure personal or household carbon dioxide emission, there are already plenty of carbon footprint calculators available on the web. Most of these calculators use quantitative models to estimate carbon emission caused by a user's activities. Although these calculators can promote public awareness regarding carbon emission due to an individual's behavior, there are concerns about the consistency and transparency of these existing CO2 calculators. Apart from a small group of smart phone based carbon footprint calculator …
Studying The Handling Of Heat Stressed Cattle Using The Additive Bi-Logistic Model To Fit Body Temperature,
2011
University of Nebraska-Lincoln
Studying The Handling Of Heat Stressed Cattle Using The Additive Bi-Logistic Model To Fit Body Temperature, Fan Yang
Department of Statistics: Dissertations, Theses, and Student Research
Daily activities consume the energy of heifers, subsequently causing an elevation of body temperature, depending on the ambient conditions. A better understanding of the dynamics of body temperature (Tb) would be helpful when deciding how to process and handle heifers. It would also lead to specific recommendations on moving heifers under different ambient conditions, especially during the summer. In this study, a bi-logistic mixed model is used to describe the dynamics of Tb during the moving event. Data were taken from heifers in pens located at different distances from the heifer work station on four separate summer days under hot …
A Stochastic Version Of The Em Algorithm To Analyze Multivariate Skew-Normal Data With Missing Responses,
2011
Islamic Azad University
A Stochastic Version Of The Em Algorithm To Analyze Multivariate Skew-Normal Data With Missing Responses, M. Khounsiavash, M. Ganjali, T. Baghfalaki
Applications and Applied Mathematics: An International Journal (AAM)
In this paper an algorithm called SEM, which is a stochastic version of the EM algorithm, is used to analyze multivariate skew-normal data with intermittent missing values. Also, a multivariate selection model framework for modeling of both missing and response mechanisms is formulated. By the SEM algorithm missing values of responses are inputed by the conditional distribution of missing values given observed data and then the log-likelihood of the pseudocomplete data is maximized. The algorithm is iterated until convergence of parameter estimates. Results of an application are also reported where a Bootstrap approach is used to compute the standard error …
Applying Gmdh-Type Neural Network And Genetic Algorithm For Stock Price Prediction Of Iranian Cement Sector,
2011
Islamic Azad University
Applying Gmdh-Type Neural Network And Genetic Algorithm For Stock Price Prediction Of Iranian Cement Sector, Saeed Fallahi, Meysam Shaverdi, Vahab Bashiri
Applications and Applied Mathematics: An International Journal (AAM)
The cement industry is one of the most important and profitable industries in Iran and great content of financial resources are investing in this sector yearly. In this paper a GMDH-type neural network and genetic algorithm is developed for stock price prediction of cement sector. For stocks price prediction by GMDH type-neural network, we are using earnings per share (EPS), Prediction Earnings Per Share (PEPS), Dividend per share (DPS), Price-earnings ratio (P/E), Earnings-price ratio (E/P) as input data and stock price as output data. For this work, data of ten cement companies is gathering from Tehran stock exchange (TSE) in …
A Group Acceptance Sampling Plans For Lifetimes Following A Marshall-Olkin Extended Exponential Distribution,
2011
Dilla University
A Group Acceptance Sampling Plans For Lifetimes Following A Marshall-Olkin Extended Exponential Distribution, G. S. Rao
Applications and Applied Mathematics: An International Journal (AAM)
In this paper, a group acceptance sampling plan is developed for a truncated life test when the lifetime of an item follows the Marshall-Olkin extended exponential distribution. The minimum number of groups required for a given group size and the acceptance number is determined when the consumer’s risk and the test termination time are specified. The operating characteristic values, according to various quality levels, are found and the minimum ratios of the true average life to the specified life at the specified producer’s risk are obtained. The results are explained with examples.
Reliable A-Posteriori Error Estimators For Hp-Adaptive Finite Element Approximations Of Eigenvalue/Leigenvector Problems,
2011
Durham University
Reliable A-Posteriori Error Estimators For Hp-Adaptive Finite Element Approximations Of Eigenvalue/Leigenvector Problems, Stefano Giani, Luka Grubisic, Jeffrey S. Ovall
Mathematics and Statistics Faculty Publications and Presentations
We present reliable a-posteriori error estimates for hp-adaptive finite element approxima- tions of eigenvalue/eigenvector problems. Starting from our earlier work on h adaptive finite element approximations we show a way to obtain reliable and efficient a-posteriori estimates in the hp-setting. At the core of our analysis is the reduction of the problem on the analysis of the associated boundary value problem. We start from the analysis of Wohlmuth and Melenk and combine this with our a-posteriori estimation framework to obtain eigenvalue/eigenvector approximation bounds.
An Analysis Of Breast Cancer Metastasis,
2011
California Polytechnic State University, San Luis Obispo
An Analysis Of Breast Cancer Metastasis, Jennifer Lee Gildner
Statistics
The main objective of this paper is to evaluate possible socio-economic status, clinical, and treatment associations with the occurrence of distant metastasis in Stage I – III breast cancer patients. After analysis in a logistic regression model, four variables were found to be significant with occurrence of distant metastases. These variables were: education, disease group (Triple-negative, Her2Neu-positive and Luminal A), stage at diagnosis, and concordance to chemotherapy based on the NCCN guidelines. Patients without a college degree were found to be more likely to develop distant metastasis than those with a college degree (OR = 2.46 95% CI 1.44 – …
