ut Inorganic pollutants in water By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9780128189665 electronic book Full Article
ut In china's wake : how the commodity boom transformed development strategies in the global south By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Author: Jepson, Nicholas, author.Callnumber: OnlineISBN: 9780231547598 electronic book Full Article
ut Handbook of optimization in electric power distribution systems By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9783030361150 Full Article
ut Fresh-cut fruits and vegetables : technologies and mechanisms for safety control By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9780128165393 (electronic bk.) Full Article
ut Feed additives : aromatic plants and herbs in animal nutrition and health By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9780128147016 (electronic bk.) Full Article
ut Evolutionary developmental biology : a reference guide By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9783319330389 (electronic bk.) Full Article
ut Ethnoveterinary medicine : present and future concepts By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9783030322700 (electronic bk.) Full Article
ut Development of biopharmaceutical drug-device products By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9783030314156 (electronic bk.) Full Article
ut Daily routine in cosmetic dermatology By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9783319202501 Full Article
ut DNA beyond genes : from data storage and computing to nanobots, nanomedicine, and nanoelectronics By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Author: Demidov, Vadim V., authorCallnumber: OnlineISBN: 9783030364342 (electronic bk.) Full Article
ut Cutaneous biometrics By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9783319565910 (electronic bk.) Full Article
ut Cullin-RING ligases and protein neddylation : biology and therapeutics By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9789811510250 (electronic bk.) Full Article
ut Controlled and modified atmosphere for fresh and fresh-cut produce By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9780128046210 Full Article
ut Computer security : ESORICS 2019 International Workshops, IOSec, MSTEC, and FINSEC, Luxembourg City, Luxembourg, September 26-27, 2019, Revised Selected Papers By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Author: European Symposium on Research in Computer Security (24th : 2019 : Luxembourg, Luxembourg)Callnumber: OnlineISBN: 9783030420512 (electronic bk.) Full Article
ut Computed body tomography with MRI correlation By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9781496370495 (hbk.) Full Article
ut Computational processing of the Portuguese language : 14th International Conference, PROPOR 2020, Evora, Portugal, March 2-4, 2020, Proceedings By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Author: PROPOR (Conference) (14th : 2020 : Evora, Portugal)Callnumber: OnlineISBN: 9783030415051 (electronic bk.) Full Article
ut Clinical approaches in endodontic regeneration : current and emerging therapeutic perspectives By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9783319968483 (electronic bk.) Full Article
ut Bioremediation and biotechnology : sustainable approaches to pollution degradation By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9783030356910 (electronic bk.) Full Article
ut Biological invasions in South Africa By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9783030323943 (electronic bk.) Full Article
ut Atlas of mohs and frozen section cutaneous pathology By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9783319748474 978-3-319-74847-4 Full Article
ut Anaerobic utilization of hydrocarbons, oils, and lipids By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9783319503912 (electronic bk.) Full Article
ut Agri-food industry strategies for healthy diets and sustainability : new challenges in nutrition and public health By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Callnumber: OnlineISBN: 9780128172261 Full Article
ut 100 cases in clinical pharmacology, therapeutics and prescribing By dal.novanet.ca Published On :: Fri, 1 May 2020 19:44:43 -0300 Author: Layne, Kerry, author.Callnumber: OnlineISBN: 9780429624537 electronic book Full Article
ut Utah Signs SB 29 Drug Disposal Program Into Law, A Huge Step Forward... By www.prweb.com Published On :: Utah State Bill SB 29 requires environmentally friendly disposal of a lawfully possessed controlled substance. NarcX worked closely with Utah lawmakers to provide crucial guidance for the bill.(PRWeb April 08, 2020)Read the full story at https://www.prweb.com/releases/utah_signs_sb_29_drug_disposal_program_into_law_a_huge_step_forward_for_narcx/prweb17030392.htm Full Article
ut InBios receives Emergency Use Authorization for its Smart Detect... By www.prweb.com Published On :: InBios International, Inc. announces the U.S. Food and Drug Administration (FDA) issued an emergency use authorization (EUA) for its diagnostic test that can be used immediately by CLIA...(PRWeb April 08, 2020)Read the full story at https://www.prweb.com/releases/inbios_receives_emergency_use_authorization_for_its_smart_detect_sars_cov_2_rrt_pcr_kit_for_detection_of_the_virus_causing_covid_19/prweb17036897.htm Full Article
ut Almost sure uniqueness of a global minimum without convexity By projecteuclid.org Published On :: Mon, 17 Feb 2020 04:02 EST Gregory Cox. Source: The Annals of Statistics, Volume 48, Number 1, 584--606.Abstract: This paper establishes the argmin of a random objective function to be unique almost surely. This paper first formulates a general result that proves almost sure uniqueness without convexity of the objective function. The general result is then applied to a variety of applications in statistics. Four applications are discussed, including uniqueness of M-estimators, both classical likelihood and penalized likelihood estimators, and two applications of the argmin theorem, threshold regression and weak identification. Full Article
ut The multi-armed bandit problem: An efficient nonparametric solution By projecteuclid.org Published On :: Mon, 17 Feb 2020 04:02 EST Hock Peng Chan. Source: The Annals of Statistics, Volume 48, Number 1, 346--373.Abstract: Lai and Robbins ( Adv. in Appl. Math. 6 (1985) 4–22) and Lai ( Ann. Statist. 15 (1987) 1091–1114) provided efficient parametric solutions to the multi-armed bandit problem, showing that arm allocation via upper confidence bounds (UCB) achieves minimum regret. These bounds are constructed from the Kullback–Leibler information of the reward distributions, estimated from specified parametric families. In recent years, there has been renewed interest in the multi-armed bandit problem due to new applications in machine learning algorithms and data analytics. Nonparametric arm allocation procedures like $epsilon $-greedy, Boltzmann exploration and BESA were studied, and modified versions of the UCB procedure were also analyzed under nonparametric settings. However, unlike UCB these nonparametric procedures are not efficient under general parametric settings. In this paper, we propose efficient nonparametric procedures. Full Article
ut Joint convergence of sample autocovariance matrices when $p/n o 0$ with application By projecteuclid.org Published On :: Wed, 30 Oct 2019 22:03 EDT Monika Bhattacharjee, Arup Bose. Source: The Annals of Statistics, Volume 47, Number 6, 3470--3503.Abstract: Consider a high-dimensional linear time series model where the dimension $p$ and the sample size $n$ grow in such a way that $p/n o 0$. Let $hat{Gamma }_{u}$ be the $u$th order sample autocovariance matrix. We first show that the LSD of any symmetric polynomial in ${hat{Gamma }_{u},hat{Gamma }_{u}^{*},ugeq 0}$ exists under independence and moment assumptions on the driving sequence together with weak assumptions on the coefficient matrices. This LSD result, with some additional effort, implies the asymptotic normality of the trace of any polynomial in ${hat{Gamma }_{u},hat{Gamma }_{u}^{*},ugeq 0}$. We also study similar results for several independent MA processes. We show applications of the above results to statistical inference problems such as in estimation of the unknown order of a high-dimensional MA process and in graphical and significance tests for hypotheses on coefficient matrices of one or several such independent processes. Full Article
ut Statistical inference for autoregressive models under heteroscedasticity of unknown form By projecteuclid.org Published On :: Wed, 30 Oct 2019 22:03 EDT Ke Zhu. Source: The Annals of Statistics, Volume 47, Number 6, 3185--3215.Abstract: This paper provides an entire inference procedure for the autoregressive model under (conditional) heteroscedasticity of unknown form with a finite variance. We first establish the asymptotic normality of the weighted least absolute deviations estimator (LADE) for the model. Second, we develop the random weighting (RW) method to estimate its asymptotic covariance matrix, leading to the implementation of the Wald test. Third, we construct a portmanteau test for model checking, and use the RW method to obtain its critical values. As a special weighted LADE, the feasible adaptive LADE (ALADE) is proposed and proved to have the same efficiency as its infeasible counterpart. The importance of our entire methodology based on the feasible ALADE is illustrated by simulation results and the real data analysis on three U.S. economic data sets. Full Article
ut Distributed estimation of principal eigenspaces By projecteuclid.org Published On :: Wed, 30 Oct 2019 22:03 EDT Jianqing Fan, Dong Wang, Kaizheng Wang, Ziwei Zhu. Source: The Annals of Statistics, Volume 47, Number 6, 3009--3031.Abstract: Principal component analysis (PCA) is fundamental to statistical machine learning. It extracts latent principal factors that contribute to the most variation of the data. When data are stored across multiple machines, however, communication cost can prohibit the computation of PCA in a central location and distributed algorithms for PCA are thus needed. This paper proposes and studies a distributed PCA algorithm: each node machine computes the top $K$ eigenvectors and transmits them to the central server; the central server then aggregates the information from all the node machines and conducts a PCA based on the aggregated information. We investigate the bias and variance for the resulting distributed estimator of the top $K$ eigenvectors. In particular, we show that for distributions with symmetric innovation, the empirical top eigenspaces are unbiased, and hence the distributed PCA is “unbiased.” We derive the rate of convergence for distributed PCA estimators, which depends explicitly on the effective rank of covariance, eigengap, and the number of machines. We show that when the number of machines is not unreasonably large, the distributed PCA performs as well as the whole sample PCA, even without full access of whole data. The theoretical results are verified by an extensive simulation study. We also extend our analysis to the heterogeneous case where the population covariance matrices are different across local machines but share similar top eigenstructures. Full Article
ut Eigenvalue distributions of variance components estimators in high-dimensional random effects models By projecteuclid.org Published On :: Fri, 02 Aug 2019 22:04 EDT Zhou Fan, Iain M. Johnstone. Source: The Annals of Statistics, Volume 47, Number 5, 2855--2886.Abstract: We study the spectra of MANOVA estimators for variance component covariance matrices in multivariate random effects models. When the dimensionality of the observations is large and comparable to the number of realizations of each random effect, we show that the empirical spectra of such estimators are well approximated by deterministic laws. The Stieltjes transforms of these laws are characterized by systems of fixed-point equations, which are numerically solvable by a simple iterative procedure. Our proof uses operator-valued free probability theory, and we establish a general asymptotic freeness result for families of rectangular orthogonally invariant random matrices, which is of independent interest. Our work is motivated in part by the estimation of components of covariance between multiple phenotypic traits in quantitative genetics, and we specialize our results to common experimental designs that arise in this application. Full Article
ut grid computing By looselycoupled.com Published On :: 2004-08-30T00:00:00-00:00 Pooled computer resources. Grid computing, or simply grid, is the generic term given to techniques and technologies designed to make pools of distributed computer resources available on-demand. Grid computing was originally conceived by research scientists as a way of combining computers across a network to form a distributed supercomputer to tackle complex computations. In the commercial world, grid aims to maximize the utilization of an organization's computing resources by making them shareable across applications (sometimes called virtualization) and, potentially, provide computing on demand to third parties as a utility service. When used with specifications such as WSRF and WS-Notification, grid resources can appear as web services within a service-oriented architecture. Full Article
ut Estimating and forecasting the smoking-attributable mortality fraction for both genders jointly in over 60 countries By projecteuclid.org Published On :: Wed, 15 Apr 2020 22:05 EDT Yicheng Li, Adrian E. Raftery. Source: The Annals of Applied Statistics, Volume 14, Number 1, 381--408.Abstract: Smoking is one of the leading preventable threats to human health and a major risk factor for lung cancer, upper aerodigestive cancer and chronic obstructive pulmonary disease. Estimating and forecasting the smoking attributable fraction (SAF) of mortality can yield insights into smoking epidemics and also provide a basis for more accurate mortality and life expectancy projection. Peto et al. ( Lancet 339 (1992) 1268–1278) proposed a method to estimate the SAF using the lung cancer mortality rate as an indicator of exposure to smoking in the population of interest. Here, we use the same method to estimate the all-age SAF (ASAF) for both genders for over 60 countries. We document a strong and cross-nationally consistent pattern of the evolution of the SAF over time. We use this as the basis for a new Bayesian hierarchical model to project future male and female ASAF from over 60 countries simultaneously. This gives forecasts as well as predictive distributions that can be used to find uncertainty intervals for any quantity of interest. We assess the model using out-of-sample predictive validation and find that it provides good forecasts and well-calibrated forecast intervals, comparing favorably with other methods. Full Article
ut Regression for copula-linked compound distributions with applications in modeling aggregate insurance claims By projecteuclid.org Published On :: Wed, 15 Apr 2020 22:05 EDT Peng Shi, Zifeng Zhao. Source: The Annals of Applied Statistics, Volume 14, Number 1, 357--380.Abstract: In actuarial research a task of particular interest and importance is to predict the loss cost for individual risks so that informative decisions are made in various insurance operations such as underwriting, ratemaking and capital management. The loss cost is typically viewed to follow a compound distribution where the summation of the severity variables is stopped by the frequency variable. A challenging issue in modeling such outcomes is to accommodate the potential dependence between the number of claims and the size of each individual claim. In this article we introduce a novel regression framework for compound distributions that uses a copula to accommodate the association between the frequency and the severity variables and, thus, allows for arbitrary dependence between the two components. We further show that the new model is very flexible and is easily modified to account for incomplete data due to censoring or truncation. The flexibility of the proposed model is illustrated using both simulated and real data sets. In the analysis of granular claims data from property insurance, we find substantive negative relationship between the number and the size of insurance claims. In addition, we demonstrate that ignoring the frequency-severity association could lead to biased decision-making in insurance operations. Full Article
ut Modeling wildfire ignition origins in southern California using linear network point processes By projecteuclid.org Published On :: Wed, 15 Apr 2020 22:05 EDT Medha Uppala, Mark S. Handcock. Source: The Annals of Applied Statistics, Volume 14, Number 1, 339--356.Abstract: This paper focuses on spatial and temporal modeling of point processes on linear networks. Point processes on linear networks can simply be defined as point events occurring on or near line segment network structures embedded in a certain space. A separable modeling framework is introduced that posits separate formation and dissolution models of point processes on linear networks over time. While the model was inspired by spider web building activity in brick mortar lines, the focus is on modeling wildfire ignition origins near road networks over a span of 14 years. As most wildfires in California have human-related origins, modeling the origin locations with respect to the road network provides insight into how human, vehicular and structural densities affect ignition occurrence. Model results show that roads that traverse different types of regions such as residential, interface and wildland regions have higher ignition intensities compared to roads that only exist in each of the mentioned region types. Full Article
ut Bayesian factor models for probabilistic cause of death assessment with verbal autopsies By projecteuclid.org Published On :: Wed, 15 Apr 2020 22:05 EDT Tsuyoshi Kunihama, Zehang Richard Li, Samuel J. Clark, Tyler H. McCormick. Source: The Annals of Applied Statistics, Volume 14, Number 1, 241--256.Abstract: The distribution of deaths by cause provides crucial information for public health planning, response and evaluation. About 60% of deaths globally are not registered or given a cause, limiting our ability to understand disease epidemiology. Verbal autopsy (VA) surveys are increasingly used in such settings to collect information on the signs, symptoms and medical history of people who have recently died. This article develops a novel Bayesian method for estimation of population distributions of deaths by cause using verbal autopsy data. The proposed approach is based on a multivariate probit model where associations among items in questionnaires are flexibly induced by latent factors. Using the Population Health Metrics Research Consortium labeled data that include both VA and medically certified causes of death, we assess performance of the proposed method. Further, we estimate important questionnaire items that are highly associated with causes of death. This framework provides insights that will simplify future data Full Article
ut A hierarchical Bayesian model for predicting ecological interactions using scaled evolutionary relationships By projecteuclid.org Published On :: Wed, 15 Apr 2020 22:05 EDT Mohamad Elmasri, Maxwell J. Farrell, T. Jonathan Davies, David A. Stephens. Source: The Annals of Applied Statistics, Volume 14, Number 1, 221--240.Abstract: Identifying undocumented or potential future interactions among species is a challenge facing modern ecologists. Recent link prediction methods rely on trait data; however, large species interaction databases are typically sparse and covariates are limited to only a fraction of species. On the other hand, evolutionary relationships, encoded as phylogenetic trees, can act as proxies for underlying traits and historical patterns of parasite sharing among hosts. We show that, using a network-based conditional model, phylogenetic information provides strong predictive power in a recently published global database of host-parasite interactions. By scaling the phylogeny using an evolutionary model, our method allows for biological interpretation often missing from latent variable models. To further improve on the phylogeny-only model, we combine a hierarchical Bayesian latent score framework for bipartite graphs that accounts for the number of interactions per species with host dependence informed by phylogeny. Combining the two information sources yields significant improvement in predictive accuracy over each of the submodels alone. As many interaction networks are constructed from presence-only data, we extend the model by integrating a correction mechanism for missing interactions which proves valuable in reducing uncertainty in unobserved interactions. Full Article
ut SHOPPER: A probabilistic model of consumer choice with substitutes and complements By projecteuclid.org Published On :: Wed, 15 Apr 2020 22:05 EDT Francisco J. R. Ruiz, Susan Athey, David M. Blei. Source: The Annals of Applied Statistics, Volume 14, Number 1, 1--27.Abstract: We develop SHOPPER, a sequential probabilistic model of shopping data. SHOPPER uses interpretable components to model the forces that drive how a customer chooses products; in particular, we designed SHOPPER to capture how items interact with other items. We develop an efficient posterior inference algorithm to estimate these forces from large-scale data, and we analyze a large dataset from a major chain grocery store. We are interested in answering counterfactual queries about changes in prices. We found that SHOPPER provides accurate predictions even under price interventions, and that it helps identify complementary and substitutable pairs of products. Full Article
ut On Bayesian new edge prediction and anomaly detection in computer networks By projecteuclid.org Published On :: Wed, 27 Nov 2019 22:01 EST Silvia Metelli, Nicholas Heard. Source: The Annals of Applied Statistics, Volume 13, Number 4, 2586--2610.Abstract: Monitoring computer network traffic for anomalous behaviour presents an important security challenge. Arrivals of new edges in a network graph represent connections between a client and server pair not previously observed, and in rare cases these might suggest the presence of intruders or malicious implants. We propose a Bayesian model and anomaly detection method for simultaneously characterising existing network structure and modelling likely new edge formation. The method is demonstrated on real computer network authentication data and successfully identifies some machines which are known to be compromised. Full Article
ut Scalable high-resolution forecasting of sparse spatiotemporal events with kernel methods: A winning solution to the NIJ “Real-Time Crime Forecasting Challenge” By projecteuclid.org Published On :: Wed, 27 Nov 2019 22:01 EST Seth Flaxman, Michael Chirico, Pau Pereira, Charles Loeffler. Source: The Annals of Applied Statistics, Volume 13, Number 4, 2564--2585.Abstract: We propose a generic spatiotemporal event forecasting method which we developed for the National Institute of Justice’s (NIJ) Real-Time Crime Forecasting Challenge (National Institute of Justice (2017)). Our method is a spatiotemporal forecasting model combining scalable randomized Reproducing Kernel Hilbert Space (RKHS) methods for approximating Gaussian processes with autoregressive smoothing kernels in a regularized supervised learning framework. While the smoothing kernels capture the two main approaches in current use in the field of crime forecasting, kernel density estimation (KDE) and self-exciting point process (SEPP) models, the RKHS component of the model can be understood as an approximation to the popular log-Gaussian Cox Process model. For inference, we discretize the spatiotemporal point pattern and learn a log-intensity function using the Poisson likelihood and highly efficient gradient-based optimization methods. Model hyperparameters including quality of RKHS approximation, spatial and temporal kernel lengthscales, number of autoregressive lags and bandwidths for smoothing kernels as well as cell shape, size and rotation, were learned using cross validation. Resulting predictions significantly exceeded baseline KDE estimates and SEPP models for sparse events. Full Article
ut Outline analyses of the called strike zone in Major League Baseball By projecteuclid.org Published On :: Wed, 27 Nov 2019 22:01 EST Dale L. Zimmerman, Jun Tang, Rui Huang. Source: The Annals of Applied Statistics, Volume 13, Number 4, 2416--2451.Abstract: We extend statistical shape analytic methods known as outline analysis for application to the strike zone, a central feature of the game of baseball. Although the strike zone is rigorously defined by Major League Baseball’s official rules, umpires make mistakes in calling pitches as strikes (and balls) and may even adhere to a strike zone somewhat different than that prescribed by the rule book. Our methods yield inference on geometric attributes (centroid, dimensions, orientation and shape) of this “called strike zone” (CSZ) and on the effects that years, umpires, player attributes, game situation factors and their interactions have on those attributes. The methodology consists of first using kernel discriminant analysis to determine a noisy outline representing the CSZ corresponding to each factor combination, then fitting existing elliptic Fourier and new generalized superelliptic models for closed curves to that outline and finally analyzing the fitted model coefficients using standard methods of regression analysis, factorial analysis of variance and variance component estimation. We apply these methods to PITCHf/x data comprising more than three million called pitches from the 2008–2016 Major League Baseball seasons to address numerous questions about the CSZ. We find that all geometric attributes of the CSZ, except its size, became significantly more like those of the rule-book strike zone from 2008–2016 and that several player attribute/game situation factors had statistically and practically significant effects on many of them. We also establish that the variation in the horizontal center, width and area of an individual umpire’s CSZ from pitch to pitch is smaller than their variation among CSZs from different umpires. Full Article
ut Microsimulation model calibration using incremental mixture approximate Bayesian computation By projecteuclid.org Published On :: Wed, 27 Nov 2019 22:01 EST Carolyn M. Rutter, Jonathan Ozik, Maria DeYoreo, Nicholson Collier. Source: The Annals of Applied Statistics, Volume 13, Number 4, 2189--2212.Abstract: Microsimulation models (MSMs) are used to inform policy by predicting population-level outcomes under different scenarios. MSMs simulate individual-level event histories that mark the disease process (such as the development of cancer) and the effect of policy actions (such as screening) on these events. MSMs often have many unknown parameters; calibration is the process of searching the parameter space to select parameters that result in accurate MSM prediction of a wide range of targets. We develop Incremental Mixture Approximate Bayesian Computation (IMABC) for MSM calibration which results in a simulated sample from the posterior distribution of model parameters given calibration targets. IMABC begins with a rejection-based ABC step, drawing a sample of points from the prior distribution of model parameters and accepting points that result in simulated targets that are near observed targets. Next, the sample is iteratively updated by drawing additional points from a mixture of multivariate normal distributions and accepting points that result in accurate predictions. Posterior estimates are obtained by weighting the final set of accepted points to account for the adaptive sampling scheme. We demonstrate IMABC by calibrating CRC-SPIN 2.0, an updated version of a MSM for colorectal cancer (CRC) that has been used to inform national CRC screening guidelines. Full Article
ut Sequential decision model for inference and prediction on nonuniform hypergraphs with application to knot matching from computational forestry By projecteuclid.org Published On :: Wed, 16 Oct 2019 22:03 EDT Seong-Hwan Jun, Samuel W. K. Wong, James V. Zidek, Alexandre Bouchard-Côté. Source: The Annals of Applied Statistics, Volume 13, Number 3, 1678--1707.Abstract: In this paper, we consider the knot-matching problem arising in computational forestry. The knot-matching problem is an important problem that needs to be solved to advance the state of the art in automatic strength prediction of lumber. We show that this problem can be formulated as a quadripartite matching problem and develop a sequential decision model that admits efficient parameter estimation along with a sequential Monte Carlo sampler on graph matching that can be utilized for rapid sampling of graph matching. We demonstrate the effectiveness of our methods on 30 manually annotated boards and present findings from various simulation studies to provide further evidence supporting the efficacy of our methods. Full Article
ut Modeling seasonality and serial dependence of electricity price curves with warping functional autoregressive dynamics By projecteuclid.org Published On :: Wed, 16 Oct 2019 22:03 EDT Ying Chen, J. S. Marron, Jiejie Zhang. Source: The Annals of Applied Statistics, Volume 13, Number 3, 1590--1616.Abstract: Electricity prices are high dimensional, serially dependent and have seasonal variations. We propose a Warping Functional AutoRegressive (WFAR) model that simultaneously accounts for the cross time-dependence and seasonal variations of the large dimensional data. In particular, electricity price curves are obtained by smoothing over the $24$ discrete hourly prices on each day. In the functional domain, seasonal phase variations are separated from level amplitude changes in a warping process with the Fisher–Rao distance metric, and the aligned (season-adjusted) electricity price curves are modeled in the functional autoregression framework. In a real application, the WFAR model provides superior out-of-sample forecast accuracy in both a normal functioning market, Nord Pool, and an extreme situation, the California market. The forecast performance as well as the relative accuracy improvement are stable for different markets and different time periods. Full Article
ut Distributional regression forests for probabilistic precipitation forecasting in complex terrain By projecteuclid.org Published On :: Wed, 16 Oct 2019 22:03 EDT Lisa Schlosser, Torsten Hothorn, Reto Stauffer, Achim Zeileis. Source: The Annals of Applied Statistics, Volume 13, Number 3, 1564--1589.Abstract: To obtain a probabilistic model for a dependent variable based on some set of explanatory variables, a distributional approach is often adopted where the parameters of the distribution are linked to regressors. In many classical models this only captures the location of the distribution but over the last decade there has been increasing interest in distributional regression approaches modeling all parameters including location, scale and shape. Notably, so-called nonhomogeneous Gaussian regression (NGR) models both mean and variance of a Gaussian response and is particularly popular in weather forecasting. Moreover, generalized additive models for location, scale and shape (GAMLSS) provide a framework where each distribution parameter is modeled separately capturing smooth linear or nonlinear effects. However, when variable selection is required and/or there are nonsmooth dependencies or interactions (especially unknown or of high-order), it is challenging to establish a good GAMLSS. A natural alternative in these situations would be the application of regression trees or random forests but, so far, no general distributional framework is available for these. Therefore, a framework for distributional regression trees and forests is proposed that blends regression trees and random forests with classical distributions from the GAMLSS framework as well as their censored or truncated counterparts. To illustrate these novel approaches in practice, they are employed to obtain probabilistic precipitation forecasts at numerous sites in a mountainous region (Tyrol, Austria) based on a large number of numerical weather prediction quantities. It is shown that the novel distributional regression forests automatically select variables and interactions, performing on par or often even better than GAMLSS specified either through prior meteorological knowledge or a computationally more demanding boosting approach. Full Article
ut Fast dynamic nonparametric distribution tracking in electron microscopic data By projecteuclid.org Published On :: Wed, 16 Oct 2019 22:03 EDT Yanjun Qian, Jianhua Z. Huang, Chiwoo Park, Yu Ding. Source: The Annals of Applied Statistics, Volume 13, Number 3, 1537--1563.Abstract: In situ transmission electron microscope (TEM) adds a promising instrument to the exploration of the nanoscale world, allowing motion pictures to be taken while nano objects are initiating, crystalizing and morphing into different sizes and shapes. To enable in-process control of nanocrystal production, this technology innovation hinges upon a solution addressing a statistical problem, which is the capability of online tracking a dynamic, time-varying probability distribution reflecting the nanocrystal growth. Because no known parametric density functions can adequately describe the evolving distribution, a nonparametric approach is inevitable. Towards this objective, we propose to incorporate the dynamic evolution of the normalized particle size distribution into a state space model, in which the density function is represented by a linear combination of B-splines and the spline coefficients are treated as states. The closed-form algorithm runs online updates faster than the frame rate of the in situ TEM video, making it suitable for in-process control purpose. Imposing the constraints of curve smoothness and temporal continuity improves the accuracy and robustness while tracking the probability distribution. We test our method on three published TEM videos. For all of them, the proposed method is able to outperform several alternative approaches. Full Article
ut The classification permutation test: A flexible approach to testing for covariate imbalance in observational studies By projecteuclid.org Published On :: Wed, 16 Oct 2019 22:03 EDT Johann Gagnon-Bartsch, Yotam Shem-Tov. Source: The Annals of Applied Statistics, Volume 13, Number 3, 1464--1483.Abstract: The gold standard for identifying causal relationships is a randomized controlled experiment. In many applications in the social sciences and medicine, the researcher does not control the assignment mechanism and instead may rely upon natural experiments or matching methods as a substitute to experimental randomization. The standard testable implication of random assignment is covariate balance between the treated and control units. Covariate balance is commonly used to validate the claim of as good as random assignment. We propose a new nonparametric test of covariate balance. Our Classification Permutation Test (CPT) is based on a combination of classification methods (e.g., random forests) with Fisherian permutation inference. We revisit four real data examples and present Monte Carlo power simulations to demonstrate the applicability of the CPT relative to other nonparametric tests of equality of multivariate distributions. Full Article
ut Imputation and post-selection inference in models with missing data: An application to colorectal cancer surveillance guidelines By projecteuclid.org Published On :: Wed, 16 Oct 2019 22:03 EDT Lin Liu, Yuqi Qiu, Loki Natarajan, Karen Messer. Source: The Annals of Applied Statistics, Volume 13, Number 3, 1370--1396.Abstract: It is common to encounter missing data among the potential predictor variables in the setting of model selection. For example, in a recent study we attempted to improve the US guidelines for risk stratification after screening colonoscopy ( Cancer Causes Control 27 (2016) 1175–1185), with the aim to help reduce both overuse and underuse of follow-on surveillance colonoscopy. The goal was to incorporate selected additional informative variables into a neoplasia risk-prediction model, going beyond the three currently established risk factors, using a large dataset pooled from seven different prospective studies in North America. Unfortunately, not all candidate variables were collected in all studies, so that one or more important potential predictors were missing on over half of the subjects. Thus, while variable selection was a main focus of the study, it was necessary to address the substantial amount of missing data. Multiple imputation can effectively address missing data, and there are also good approaches to incorporate the variable selection process into model-based confidence intervals. However, there is not consensus on appropriate methods of inference which address both issues simultaneously. Our goal here is to study the properties of model-based confidence intervals in the setting of imputation for missing data followed by variable selection. We use both simulation and theory to compare three approaches to such post-imputation-selection inference: a multiple-imputation approach based on Rubin’s Rules for variance estimation ( Comput. Statist. Data Anal. 71 (2014) 758–770); a single imputation-selection followed by bootstrap percentile confidence intervals; and a new bootstrap model-averaging approach presented here, following Efron ( J. Amer. Statist. Assoc. 109 (2014) 991–1007). We investigate relative strengths and weaknesses of each method. The “Rubin’s Rules” multiple imputation estimator can have severe undercoverage, and is not recommended. The imputation-selection estimator with bootstrap percentile confidence intervals works well. The bootstrap-model-averaged estimator, with the “Efron’s Rules” estimated variance, may be preferred if the true effect sizes are moderate. We apply these results to the colorectal neoplasia risk-prediction problem which motivated the present work. Full Article
ut Noncommutative Lebesgue decomposition and contiguity with applications in quantum statistics By projecteuclid.org Published On :: Mon, 27 Apr 2020 04:02 EDT Akio Fujiwara, Koichi Yamagata. Source: Bernoulli, Volume 26, Number 3, 2105--2142.Abstract: We herein develop a theory of contiguity in the quantum domain based upon a novel quantum analogue of the Lebesgue decomposition. The theory thus formulated is pertinent to the weak quantum local asymptotic normality introduced in the previous paper [Yamagata, Fujiwara, and Gill, Ann. Statist. 41 (2013) 2197–2217], yielding substantial enlargement of the scope of quantum statistics. Full Article
ut On the probability distribution of the local times of diagonally operator-self-similar Gaussian fields with stationary increments By projecteuclid.org Published On :: Fri, 31 Jan 2020 04:06 EST Kamran Kalbasi, Thomas Mountford. Source: Bernoulli, Volume 26, Number 2, 1504--1534.Abstract: In this paper, we study the local times of vector-valued Gaussian fields that are ‘diagonally operator-self-similar’ and whose increments are stationary. Denoting the local time of such a Gaussian field around the spatial origin and over the temporal unit hypercube by $Z$, we show that there exists $lambdain(0,1)$ such that under some quite weak conditions, $lim_{n ightarrow+infty}frac{sqrt[n]{mathbb{E}(Z^{n})}}{n^{lambda}}$ and $lim_{x ightarrow+infty}frac{-logmathbb{P}(Z>x)}{x^{frac{1}{lambda}}}$ both exist and are strictly positive (possibly $+infty$). Moreover, we show that if the underlying Gaussian field is ‘strongly locally nondeterministic’, the above limits will be finite as well. These results are then applied to establish similar statements for the intersection local times of diagonally operator-self-similar Gaussian fields with stationary increments. Full Article