Guanhua Chen, Yufeng Liu, Dinggang Shen, Michael R Kosorok
{"title":"Composite large margin classifiers with latent subclasses for heterogeneous biomedical data.","authors":"Guanhua Chen, Yufeng Liu, Dinggang Shen, Michael R Kosorok","doi":"10.1002/sam.11300","DOIUrl":"10.1002/sam.11300","url":null,"abstract":"<p><p>High dimensional classification problems are prevalent in a wide range of modern scientific applications. Despite a large number of candidate classification techniques available to use, practitioners often face a dilemma of choosing between linear and general nonlinear classifiers. Specifically, simple linear classifiers have good interpretability, but may have limitations in handling data with complex structures. In contrast, general nonlinear classifiers are more flexible, but may lose interpretability and have higher tendency for overfitting. In this paper, we consider data with potential latent subgroups in the classes of interest. We propose a new method, namely the Composite Large Margin Classifier (CLM), to address the issue of classification with latent subclasses. The CLM aims to find three linear functions simultaneously: one linear function to split the data into two parts, with each part being classified by a different linear classifier. Our method has comparable prediction accuracy to a general nonlinear classifier, and it maintains the interpretability of traditional linear classifiers. We demonstrate the competitive performance of the CLM through comparisons with several existing linear and nonlinear classifiers by Monte Carlo experiments. Analysis of the Alzheimer's disease classification problem using CLM not only provides a lower classification error in discriminating cases and controls, but also identifies subclasses in controls that are more likely to develop the disease in the future.</p>","PeriodicalId":48684,"journal":{"name":"Statistical Analysis and Data Mining","volume":"9 2","pages":"75-88"},"PeriodicalIF":1.3,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4912001/pdf/nihms737408.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34597836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Feature Import Vector Machine: A General Classifier with Flexible Feature Selection.","authors":"Samiran Ghosh, Yazhen Wang","doi":"10.1002/sam.11259","DOIUrl":"https://doi.org/10.1002/sam.11259","url":null,"abstract":"<p><p>The support vector machine (SVM) and other reproducing kernel Hilbert space (RKHS) based classifier systems are drawing much attention recently due to its robustness and generalization capability. General theme here is to construct classifiers based on the training data in a high dimensional space by using all available dimensions. The SVM achieves huge data compression by selecting only few observations which lie close to the boundary of the classifier function. However when the number of observations are not very large (small <i>n</i>) but the number of dimensions/features are large (large <i>p</i>), then it is not necessary that all available features are of equal importance in the classification context. Possible selection of an useful fraction of the available features may result in huge data compression. In this paper we propose an algorithmic approach by means of which such an <i>optimal</i> set of features could be selected. In short, we reverse the traditional sequential observation selection strategy of SVM to that of sequential feature selection. To achieve this we have modified the solution proposed by Zhu and Hastie (2005) in the context of import vector machine (IVM), to select an <i>optimal</i> sub-dimensional model to build the final classifier with sufficient accuracy.</p>","PeriodicalId":48684,"journal":{"name":"Statistical Analysis and Data Mining","volume":"8 1","pages":"49-63"},"PeriodicalIF":1.3,"publicationDate":"2015-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/sam.11259","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34463560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yolanda Hagar, David Albers, Rimma Pivovarov, Herbert Chase, Vanja Dukic, Noémie Elhadad
{"title":"Survival Analysis with Electronic Health Record Data: Experiments with Chronic Kidney Disease.","authors":"Yolanda Hagar, David Albers, Rimma Pivovarov, Herbert Chase, Vanja Dukic, Noémie Elhadad","doi":"10.1002/sam.11236","DOIUrl":"10.1002/sam.11236","url":null,"abstract":"<p><p>This paper presents a detailed survival analysis for chronic kidney disease (CKD). The analysis is based on the EHR data comprising almost two decades of clinical observations collected at New York-Presbyterian, a large hospital in New York City with one of the oldest electronic health records in the United States. Our survival analysis approach centers around Bayesian multiresolution hazard modeling, with an objective to capture the changing hazard of CKD over time, adjusted for patient clinical covariates and kidney-related laboratory tests. Special attention is paid to statistical issues common to all EHR data, such as cohort definition, missing data and censoring, variable selection, and potential for joint survival and longitudinal modeling, all of which are discussed alone and within the EHR CKD context.</p>","PeriodicalId":48684,"journal":{"name":"Statistical Analysis and Data Mining","volume":"7 5","pages":"385-403"},"PeriodicalIF":2.1,"publicationDate":"2014-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8112603/pdf/nihms-1697574.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38975743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multi-transfer: Transfer learning with multiple views and multiple sources","authors":"Ben Tan, Erheng Zhong, E. Xiang, Qiang Yang","doi":"10.1137/1.9781611972832.27","DOIUrl":"https://doi.org/10.1137/1.9781611972832.27","url":null,"abstract":"Transfer learning, which aims to help the learning task in a target domain by leveraging knowledge from auxiliary domains, has been demonstrated to be effective in different applications, e.g., text mining, sentiment analysis, etc. In addition, in many real-world applications, auxiliary data are described from multiple perspectives and usually carried by multiple sources. For example, to help classify videos on Youtube, which include three views/perspectives: image, voice and subtitles, one may borrow data from Flickr, Last.FM and Google News. Although any single instance in these domains can only cover a part of the views available on Youtube, actually the piece of information carried by them may compensate with each other. In this paper, we define this transfer learning problem as Transfer Learning with Multiple Views and Multiple Sources. As different sources may have different probability distributions and different views may be compensate or inconsistent with each other, merging all data in a simplistic manner will not give optimal result. Thus, we propose a novel algorithm to leverage knowledge from different views and sources collaboratively, by letting different views from different sources complement each other through a co-training style framework, while revise the distribution differences in different domains. We conduct empirical studies on several real-world datasets to show that the proposed approach can improve the classification accuracy by up to 8% against different state-of-the-art baselines.","PeriodicalId":48684,"journal":{"name":"Statistical Analysis and Data Mining","volume":"34 1","pages":"282-293"},"PeriodicalIF":1.3,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83621622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stacey J Winham, Robert R Freimuth, Joanna M Biernacka
{"title":"A Weighted Random Forests Approach to Improve Predictive Performance.","authors":"Stacey J Winham, Robert R Freimuth, Joanna M Biernacka","doi":"10.1002/sam.11196","DOIUrl":"https://doi.org/10.1002/sam.11196","url":null,"abstract":"<p><p>Identifying genetic variants associated with complex disease in high-dimensional data is a challenging problem, and complicated etiologies such as gene-gene interactions are often ignored in analyses. The data-mining method Random Forests (RF) can handle high-dimensions; however, in high-dimensional data, RF is not an effective filter for identifying risk factors associated with the disease trait via complex genetic models such as gene-gene interactions without strong marginal components. Here we propose an extension called Weighted Random Forests (wRF), which incorporates tree-level weights to emphasize more accurate trees in prediction and calculation of variable importance. We demonstrate through simulation and application to data from a genetic study of addiction that wRF can outperform RF in high-dimensional data, although the improvements are modest and limited to situations with effect sizes that are larger than what is realistic in genetics of complex disease. Thus, the current implementation of wRF is unlikely to improve detection of relevant predictors in high-dimensional genetic data, but may be applicable in other situations where larger effect sizes are anticipated.</p>","PeriodicalId":48684,"journal":{"name":"Statistical Analysis and Data Mining","volume":"6 6","pages":"496-505"},"PeriodicalIF":1.3,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/sam.11196","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32096214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Penalized Regression and Risk Prediction in Genome-Wide Association Studies.","authors":"Erin Austin, Wei Pan, Xiaotong Shen","doi":"10.1002/sam.11183","DOIUrl":"10.1002/sam.11183","url":null,"abstract":"<p><p>An important task in personalized medicine is to predict disease risk based on a person's genome, e.g. on a large number of single-nucleotide polymorphisms (SNPs). Genome-wide association studies (GWAS) make SNP and phenotype data available to researchers. A critical question for researchers is how to best predict disease risk. Penalized regression equipped with variable selection, such as LASSO and SCAD, is deemed to be promising in this setting. However, the sparsity assumption taken by the LASSO, SCAD and many other penalized regression techniques may not be applicable here: it is now hypothesized that many common diseases are associated with many SNPs with small to moderate effects. In this article, we use the GWAS data from the Wellcome Trust Case Control Consortium (WTCCC) to investigate the performance of various unpenalized and penalized regression approaches under true sparse or non-sparse models. We find that in general penalized regression outperformed unpenalized regression; SCAD, TLP and LASSO performed best for sparse models, while elastic net regression was the winner, followed by ridge, TLP and LASSO, for non-sparse models.</p>","PeriodicalId":48684,"journal":{"name":"Statistical Analysis and Data Mining","volume":"6 4","pages":""},"PeriodicalIF":1.3,"publicationDate":"2013-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3859439/pdf/nihms534715.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31963889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Genevera I Allen, Christine Peterson, Marina Vannucci, Mirjana Maletić-Savatić
{"title":"Regularized Partial Least Squares with an Application to NMR Spectroscopy.","authors":"Genevera I Allen, Christine Peterson, Marina Vannucci, Mirjana Maletić-Savatić","doi":"10.1002/sam.11169","DOIUrl":"https://doi.org/10.1002/sam.11169","url":null,"abstract":"<p><p>High-dimensional data common in genomics, proteomics, and chemometrics often contains complicated correlation structures. Recently, partial least squares (PLS) and Sparse PLS methods have gained attention in these areas as dimension reduction techniques in the context of supervised data analysis. We introduce a framework for Regularized PLS by solving a relaxation of the SIMPLS optimization problem with penalties on the PLS loadings vectors. Our approach enjoys many advantages including flexibility, general penalties, easy interpretation of results, and fast computation in high-dimensional settings. We also outline extensions of our methods leading to novel methods for non-negative PLS and generalized PLS, an adoption of PLS for structured data. We demonstrate the utility of our methods through simulations and a case study on proton Nuclear Magnetic Resonance (NMR) spectroscopy data.</p>","PeriodicalId":48684,"journal":{"name":"Statistical Analysis and Data Mining","volume":"6 4","pages":"302-314"},"PeriodicalIF":1.3,"publicationDate":"2013-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/sam.11169","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32104846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"AAPL: Assessing Association between P-value Lists.","authors":"Tianwei Yu, Yize Zhao, Shihao Shen","doi":"10.1002/sam.11180","DOIUrl":"https://doi.org/10.1002/sam.11180","url":null,"abstract":"<p><p>Joint analyses of high-throughput datasets generate the need to assess the association between two long lists of p-values. In such p-value lists, the vast majority of the features are insignificant. Ideally contributions of features that are null in both tests should be minimized. However, by random chance their p-values are uniformly distributed between zero and one, and weak correlations of the p-values may exist due to inherent biases in the high-throughput technology used to generate the multiple datasets. Rank-based agreement test may capture such unwanted effects. Testing contingency tables generated using hard cutoffs may be sensitive to arbitrary threshold choice. We develop a novel method based on feature-level concordance using local false discovery rate. The association score enjoys straight-forward interpretation. The method shows higher statistical power to detect association between p-value lists in simulation. We demonstrate its utility using real data analysis. The R implementation of the method is available at http://userwww.service.emory.edu/~tyu8/AAPL/.</p>","PeriodicalId":48684,"journal":{"name":"Statistical Analysis and Data Mining","volume":"6 2","pages":"144-155"},"PeriodicalIF":1.3,"publicationDate":"2013-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/sam.11180","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31392998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiangxin Zhu, Max Welling, Fang Jin, John Lowengrub
{"title":"Predicting Simulation Parameters of Biological Systems Using a Gaussian Process Model.","authors":"Xiangxin Zhu, Max Welling, Fang Jin, John Lowengrub","doi":"10.1002/sam.11163","DOIUrl":"https://doi.org/10.1002/sam.11163","url":null,"abstract":"<p><p>Finding optimal parameters for simulating biological systems is usually a very difficult and expensive task in systems biology. Brute force searching is infeasible in practice because of the huge (often infinite) search space. In this article, we propose predicting the parameters efficiently by learning the relationship between system outputs and parameters using regression. However, the conventional parametric regression models suffer from two issues, thus are not applicable to this problem. First, restricting the regression function as a certain fixed type (e.g. linear, polynomial, etc.) introduces too strong assumptions that reduce the model flexibility. Second, conventional regression models fail to take into account the fact that a fixed parameter value may correspond to multiple different outputs due to the stochastic nature of most biological simulations, and the existence of a potentially large number of other factors that affect the simulation outputs. We propose a novel approach based on a Gaussian process model that addresses the two issues jointly. We apply our approach to a tumor vessel growth model and the feedback Wright-Fisher model. The experimental results show that our method can predict the parameter values of both of the two models with high accuracy.</p>","PeriodicalId":48684,"journal":{"name":"Statistical Analysis and Data Mining","volume":"5 6","pages":"509-522"},"PeriodicalIF":1.3,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/sam.11163","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31300011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}