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37,909
Dimension Reduction Using Rule Ensemble Machine Learning Methods: A Numerical Study of Three Ensemble Methods
stat.ML
Ensemble methods for supervised machine learning have become popular due to their ability to accurately predict class labels with groups of simple, lightweight "base learners." While ensembles offer computationally efficient models that have good predictive capability they tend to be large and offer little insight into...
computer science
37,910
Regularized Laplacian Estimation and Fast Eigenvector Approximation
cs.DS
Recently, Mahoney and Orecchia demonstrated that popular diffusion-based procedures to compute a quick \emph{approximation} to the first nontrivial eigenvector of a data graph Laplacian \emph{exactly} solve certain regularized Semi-Definite Programs (SDPs). In this paper, we extend that result by providing a statistica...
computer science
37,911
Positive definite matrices and the S-divergence
math.FA
Positive definite matrices abound in a dazzling variety of applications. This ubiquity can be in part attributed to their rich geometric structure: positive definite matrices form a self-dual convex cone whose strict interior is a Riemannian manifold. The manifold view is endowed with a "natural" distance function whil...
computer science
37,912
Asymptotically Independent Markov Sampling: a new MCMC scheme for Bayesian Inference
stat.CO
In Bayesian statistics, many problems can be expressed as the evaluation of the expectation of a quantity of interest with respect to the posterior distribution. Standard Monte Carlo method is often not applicable because the encountered posterior distributions cannot be sampled directly. In this case, the most popular...
computer science
37,913
Readouts for Echo-state Networks Built using Locally Regularized Orthogonal Forward Regression
stat.ML
Echo state network (ESN) is viewed as a temporal non-orthogonal expansion with pseudo-random parameters. Such expansions naturally give rise to regressors of various relevance to a teacher output. We illustrate that often only a certain amount of the generated echo-regressors effectively explain the variance of the tea...
computer science
37,914
Bayesian Optimization for Adaptive MCMC
stat.CO
This paper proposes a new randomized strategy for adaptive MCMC using Bayesian optimization. This approach applies to non-differentiable objective functions and trades off exploration and exploitation to reduce the number of potentially costly objective function evaluations. We demonstrate the strategy in the complex s...
computer science
37,915
Efficient Marginal Likelihood Computation for Gaussian Process Regression
stat.ML
In a Bayesian learning setting, the posterior distribution of a predictive model arises from a trade-off between its prior distribution and the conditional likelihood of observed data. Such distribution functions usually rely on additional hyperparameters which need to be tuned in order to achieve optimum predictive pe...
computer science
37,916
Model Selection in Undirected Graphical Models with the Elastic Net
stat.OT
Structure learning in random fields has attracted considerable attention due to its difficulty and importance in areas such as remote sensing, computational biology, natural language processing, protein networks, and social network analysis. We consider the problem of estimating the probabilistic graph structure associ...
computer science
37,917
Vector-valued Reproducing Kernel Banach Spaces with Applications to Multi-task Learning
math.FA
Motivated by multi-task machine learning with Banach spaces, we propose the notion of vector-valued reproducing kernel Banach spaces (RKBS). Basic properties of the spaces and the associated reproducing kernels are investigated. We also present feature map constructions and several concrete examples of vector-valued RK...
computer science
37,918
Combinatorial clustering and the beta negative binomial process
stat.ME
We develop a Bayesian nonparametric approach to a general family of latent class problems in which individuals can belong simultaneously to multiple classes and where each class can be exhibited multiple times by an individual. We introduce a combinatorial stochastic process known as the negative binomial process (NBP)...
computer science
37,919
Estimation of scale functions to model heteroscedasticity by support vector machines
stat.ML
A main goal of regression is to derive statistical conclusions on the conditional distribution of the output variable Y given the input values x. Two of the most important characteristics of a single distribution are location and scale. Support vector machines (SVMs) are well established to estimate location functions ...
computer science
37,920
A note on the lack of symmetry in the graphical lasso
stat.ML
The graphical lasso (glasso) is a widely-used fast algorithm for estimating sparse inverse covariance matrices. The glasso solves an L1 penalized maximum likelihood problem and is available as an R library on CRAN. The output from the glasso, a regularized covariance matrix estimate a sparse inverse covariance matrix e...
computer science
37,921
Analog Sparse Approximation with Applications to Compressed Sensing
math.OC
Recent research has shown that performance in signal processing tasks can often be significantly improved by using signal models based on sparse representations, where a signal is approximated using a small number of elements from a fixed dictionary. Unfortunately, inference in this model involves solving non-smooth op...
computer science
37,922
Joint Modeling of Multiple Related Time Series via the Beta Process
stat.ME
We propose a Bayesian nonparametric approach to the problem of jointly modeling multiple related time series. Our approach is based on the discovery of a set of latent, shared dynamical behaviors. Using a beta process prior, the size of the set and the sharing pattern are both inferred from data. We develop efficient M...
computer science
37,923
Krylov Subspace Descent for Deep Learning
stat.ML
In this paper, we propose a second order optimization method to learn models where both the dimensionality of the parameter space and the number of training samples is high. In our method, we construct on each iteration a Krylov subspace formed by the gradient and an approximation to the Hessian matrix, and then use a ...
computer science
37,924
Automatic Relevance Determination in Nonnegative Matrix Factorization with the β-Divergence
stat.ML
This paper addresses the estimation of the latent dimensionality in nonnegative matrix factorization (NMF) with the \beta-divergence. The \beta-divergence is a family of cost functions that includes the squared Euclidean distance, Kullback-Leibler and Itakura-Saito divergences as special cases. Learning the model order...
computer science
37,925
Extension of SBL Algorithms for the Recovery of Block Sparse Signals with Intra-Block Correlation
stat.ML
We examine the recovery of block sparse signals and extend the framework in two important directions; one by exploiting signals' intra-block correlation and the other by generalizing signals' block structure. We propose two families of algorithms based on the framework of block sparse Bayesian learning (BSBL). One fami...
computer science
37,926
Split HMC for Gaussian Process Models
stat.CO
In this paper, we discuss an extension of the Split Hamiltonian Monte Carlo (Split HMC) method for Gaussian process model (GPM). This method is based on splitting the Hamiltonian in a way that allows much of the movement around the state space to be done at low computational cost. To this end, we approximate the negati...
computer science
37,927
Dynamic trees for streaming and massive data contexts
stat.ME
Data collection at a massive scale is becoming ubiquitous in a wide variety of settings, from vast offline databases to streaming real-time information. Learning algorithms deployed in such contexts must rely on single-pass inference, where the data history is never revisited. In streaming contexts, learning must also ...
computer science
37,928
Approximate Computation and Implicit Regularization for Very Large-scale Data Analysis
cs.DS
Database theory and database practice are typically the domain of computer scientists who adopt what may be termed an algorithmic perspective on their data. This perspective is very different than the more statistical perspective adopted by statisticians, scientific computers, machine learners, and other who work on wh...
computer science
37,929
Sequential Design for Computer Experiments with a Flexible Bayesian Additive Model
stat.ME
In computer experiments, a mathematical model implemented on a computer is used to represent complex physical phenomena. These models, known as computer simulators, enable experimental study of a virtual representation of the complex phenomena. Simulators can be thought of as complex functions that take many inputs and...
computer science
37,930
A Short Note on Gaussian Process Modeling for Large Datasets using Graphics Processing Units
stat.CO
The graphics processing unit (GPU) has emerged as a powerful and cost effective processor for general performance computing. GPUs are capable of an order of magnitude more floating-point operations per second as compared to modern central processing units (CPUs), and thus provide a great deal of promise for computation...
computer science
37,931
Selection of tuning parameters in bridge regression models via Bayesian information criterion
stat.ME
We consider the bridge linear regression modeling, which can produce a sparse or non-sparse model. A crucial point in the model building process is the selection of adjusted parameters including a regularization parameter and a tuning parameter in bridge regression models. The choice of the adjusted parameters can be v...
computer science
37,932
Semi-blind Sparse Image Reconstruction with Application to MRFM
stat.ML
We propose a solution to the image deconvolution problem where the convolution kernel or point spread function (PSF) is assumed to be only partially known. Small perturbations generated from the model are exploited to produce a few principal components explaining the PSF uncertainty in a high dimensional space. Unlike ...
computer science
37,933
Corrected Kriging update formulae for batch-sequential data assimilation
stat.ML
Recently, a lot of effort has been paid to the efficient computation of Kriging predictors when observations are assimilated sequentially. In particular, Kriging update formulae enabling significant computational savings were derived in Barnes and Watson (1992), Gao et al. (1996), and Emery (2009). Taking advantage of ...
computer science
37,934
Convergence Properties of Kronecker Graphical Lasso Algorithms
stat.ME
This paper studies iteration convergence of Kronecker graphical lasso (KGLasso) algorithms for estimating the covariance of an i.i.d. Gaussian random sample under a sparse Kronecker-product covariance model and MSE convergence rates. The KGlasso model, originally called the transposable regularized covariance model by ...
computer science
37,935
Distributed Robust Power System State Estimation
stat.ML
Deregulation of energy markets, penetration of renewables, advanced metering capabilities, and the urge for situational awareness, all call for system-wide power system state estimation (PSSE). Implementing a centralized estimator though is practically infeasible due to the complexity scale of an interconnection, the c...
computer science
37,936
Optimally-Weighted Herding is Bayesian Quadrature
stat.ML
Herding and kernel herding are deterministic methods of choosing samples which summarise a probability distribution. A related task is choosing samples for estimating integrals using Bayesian quadrature. We show that the criterion minimised when selecting samples in kernel herding is equivalent to the posterior varianc...
computer science
37,937
Balancing Lifetime and Classification Accuracy of Wireless Sensor Networks
cs.NI
Wireless sensor networks are composed of distributed sensors that can be used for signal detection or classification. The likelihood functions of the hypotheses are often not known in advance, and decision rules have to be learned via supervised learning. A specific such algorithm is Fisher discriminant analysis (FDA),...
computer science
37,938
Efficient Algorithm for Extremely Large Multi-task Regression with Massive Structured Sparsity
stat.ML
We develop a highly scalable optimization method called "hierarchical group-thresholding" for solving a multi-task regression model with complex structured sparsity constraints on both input and output spaces. Despite the recent emergence of several efficient optimization algorithms for tackling complex sparsity-induci...
computer science
37,939
Consistent selection of tuning parameters via variable selection stability
stat.ML
Penalized regression models are popularly used in high-dimensional data analysis to conduct variable selection and model fitting simultaneously. Whereas success has been widely reported in literature, their performances largely depend on the tuning parameters that balance the trade-off between model fitting and model s...
computer science
37,940
Minerva and minepy: a C engine for the MINE suite and its R, Python and MATLAB wrappers
stat.ML
We introduce a novel implementation in ANSI C of the MINE family of algorithms for computing maximal information-based measures of dependence between two variables in large datasets, with the aim of a low memory footprint and ease of integration within bioinformatics pipelines. We provide the libraries minerva (with th...
computer science
37,941
Multiresolution Gaussian Processes
stat.ME
We propose a multiresolution Gaussian process to capture long-range, non-Markovian dependencies while allowing for abrupt changes. The multiresolution GP hierarchically couples a collection of smooth GPs, each defined over an element of a random nested partition. Long-range dependencies are captured by the top-level GP...
computer science
37,942
Augment-and-Conquer Negative Binomial Processes
stat.ML
By developing data augmentation methods unique to the negative binomial (NB) distribution, we unite seemingly disjoint count and mixture models under the NB process framework. We develop fundamental properties of the models and derive efficient Gibbs sampling inference. We show that the gamma-NB process can be reduced ...
computer science
37,943
Restricting exchangeable nonparametric distributions
stat.ME
Distributions over exchangeable matrices with infinitely many columns, such as the Indian buffet process, are useful in constructing nonparametric latent variable models. However, the distribution implied by such models over the number of features exhibited by each data point may be poorly- suited for many modeling tas...
computer science
37,944
Group descent algorithms for nonconvex penalized linear and logistic regression models with grouped predictors
stat.CO
Penalized regression is an attractive framework for variable selection problems. Often, variables possess a grouping structure, and the relevant selection problem is that of selecting groups, not individual variables. The group lasso has been proposed as a way of extending the ideas of the lasso to the problem of group...
computer science
37,945
Positivity and Transportation
stat.ML
We prove in this paper that the weighted volume of the set of integral transportation matrices between two integral histograms r and c of equal sum is a positive definite kernel of r and c when the set of considered weights forms a positive definite matrix. The computation of this quantity, despite being the subject of...
computer science
37,946
Signal Recovery in Unions of Subspaces with Applications to Compressive Imaging
stat.ML
In applications ranging from communications to genetics, signals can be modeled as lying in a union of subspaces. Under this model, signal coefficients that lie in certain subspaces are active or inactive together. The potential subspaces are known in advance, but the particular set of subspaces that are active (i.e., ...
computer science
37,947
Negative Binomial Process Count and Mixture Modeling
stat.ME
The seemingly disjoint problems of count and mixture modeling are united under the negative binomial (NB) process. A gamma process is employed to model the rate measure of a Poisson process, whose normalization provides a random probability measure for mixture modeling and whose marginalization leads to an NB process f...
computer science
37,948
Probabilistic Auto-Associative Models and Semi-Linear PCA
stat.AP
Auto-Associative models cover a large class of methods used in data analysis. In this paper, we describe the generals properties of these models when the projection component is linear and we propose and test an easy to implement Probabilistic Semi-Linear Auto- Associative model in a Gaussian setting. We show it is a g...
computer science
37,949
A Note on the SPICE Method
stat.ML
In this article, we analyze the SPICE method developed in [1], and establish its connections with other standard sparse estimation methods such as the Lasso and the LAD-Lasso. This result positions SPICE as a computationally efficient technique for the calculation of Lasso-type estimators. Conversely, this connection i...
computer science
37,950
Validation of Soft Classification Models using Partial Class Memberships: An Extended Concept of Sensitivity & Co. applied to the Grading of Astrocytoma Tissues
stat.ML
We use partial class memberships in soft classification to model uncertain labelling and mixtures of classes. Partial class memberships are not restricted to predictions, but may also occur in reference labels (ground truth, gold standard diagnosis) for training and validation data. Classifier performance is usually ...
computer science
37,951
Reconstructing Self Organizing Maps as Spider Graphs for better visual interpretation of large unstructured datasets
cs.GR
Self-Organizing Maps (SOM) are popular unsupervised artificial neural network used to reduce dimensions and visualize data. Visual interpretation from Self-Organizing Maps (SOM) has been limited due to grid approach of data representation, which makes inter-scenario analysis impossible. The paper proposes a new way to ...
computer science
37,952
A Geometric Blind Source Separation Method Based on Facet Component Analysis
math.NA
Given a set of mixtures, blind source separation attempts to retrieve the source signals without or with very little information of the the mixing process. We present a geometric approach for blind separation of nonnegative linear mixtures termed {\em facet component analysis} (FCA). The approach is based on facet iden...
computer science
37,953
A proximal Newton framework for composite minimization: Graph learning without Cholesky decompositions and matrix inversions
stat.ML
We propose an algorithmic framework for convex minimization problems of a composite function with two terms: a self-concordant function and a possibly nonsmooth regularization term. Our method is a new proximal Newton algorithm that features a local quadratic convergence rate. As a specific instance of our framework, w...
computer science
37,954
Fano schemes of generic intersections and machine learning
math.AG
We investigate Fano schemes of conditionally generic intersections, i.e. of hypersurfaces in projective space chosen generically up to additional conditions. Via a correspondence between generic properties of algebraic varieties and events in probability spaces that occur with probability one, we use the obtained resul...
computer science
37,955
Anomaly Classification with the Anti-Profile Support Vector Machine
stat.ML
We introduce the anti-profile Support Vector Machine (apSVM) as a novel algorithm to address the anomaly classification problem, an extension of anomaly detection where the goal is to distinguish data samples from a number of anomalous and heterogeneous classes based on their pattern of deviation from a normal stable c...
computer science
37,956
Supervised Classification Using Sparse Fisher's LDA
stat.ML
It is well known that in a supervised classification setting when the number of features is smaller than the number of observations, Fisher's linear discriminant rule is asymptotically Bayes. However, there are numerous modern applications where classification is needed in the high-dimensional setting. Naive implementa...
computer science
37,957
Explorative Data Analysis for Changes in Neural Activity
stat.ML
Neural recordings are nonstationary time series, i.e. their properties typically change over time. Identifying specific changes, e.g. those induced by a learning task, can shed light on the underlying neural processes. However, such changes of interest are often masked by strong unrelated changes, which can be of physi...
computer science
37,958
An Extragradient-Based Alternating Direction Method for Convex Minimization
math.OC
In this paper, we consider the problem of minimizing the sum of two convex functions subject to linear linking constraints. The classical alternating direction type methods usually assume that the two convex functions have relatively easy proximal mappings. However, many problems arising from statistics, image processi...
computer science
37,959
A note on selection stability: combining stability and prediction
stat.ME
Recently, many regularized procedures have been proposed for variable selection in linear regression, but their performance depends on the tuning parameter selection. Here a criterion for the tuning parameter selection is proposed, which combines the strength of both stability selection and cross-validation and therefo...
computer science
37,960
An improved quasar detection method in EROS-2 and MACHO LMC datasets
stat.ML
We present a new classification method for quasar identification in the EROS-2 and MACHO datasets based on a boosted version of Random Forest classifier. We use a set of variability features including parameters of a continuous auto regressive model. We prove that continuous auto regressive parameters are very importan...
computer science
37,961
High-dimensional Mixed Graphical Models
stat.ML
While graphical models for continuous data (Gaussian graphical models) and discrete data (Ising models) have been extensively studied, there is little work on graphical models linking both continuous and discrete variables (mixed data), which are common in many scientific applications. We propose a novel graphical mode...
computer science
37,962
Identifying cancer subtypes in glioblastoma by combining genomic, transcriptomic and epigenomic data
stat.ML
We present a nonparametric Bayesian method for disease subtype discovery in multi-dimensional cancer data. Our method can simultaneously analyse a wide range of data types, allowing for both agreement and disagreement between their underlying clustering structure. It includes feature selection and infers the most likel...
computer science
37,963
A Counterexample for the Validity of Using Nuclear Norm as a Convex Surrogate of Rank
stat.ML
Rank minimization has attracted a lot of attention due to its robustness in data recovery. To overcome the computational difficulty, rank is often replaced with nuclear norm. For several rank minimization problems, such a replacement has been theoretically proven to be valid, i.e., the solution to nuclear norm minimiza...
computer science
37,964
Comparison of several reweighted l1-algorithms for solving cardinality minimization problems
math.OC
Reweighted l1-algorithms have attracted a lot of attention in the field of applied mathematics. A unified framework of such algorithms has been recently proposed by Zhao and Li. In this paper we construct a few new examples of reweighted l1-methods. These functions are certain concave approximations of the l0-norm func...
computer science
37,965
Declarative Modeling and Bayesian Inference of Dark Matter Halos
stat.ML
Probabilistic programming allows specification of probabilistic models in a declarative manner. Recently, several new software systems and languages for probabilistic programming have been developed on the basis of newly developed and improved methods for approximate inference in probabilistic models. In this contribut...
computer science
37,966
Particle approximations of the score and observed information matrix for parameter estimation in state space models with linear computational cost
stat.CO
Poyiadjis et al. (2011) show how particle methods can be used to estimate both the score and the observed information matrix for state space models. These methods either suffer from a computational cost that is quadratic in the number of particles, or produce estimates whose variance increases quadratically with the am...
computer science
37,967
A Kernel Test for Three-Variable Interactions
stat.ME
We introduce kernel nonparametric tests for Lancaster three-variable interaction and for total independence, using embeddings of signed measures into a reproducing kernel Hilbert space. The resulting test statistics are straightforward to compute, and are used in powerful interaction tests, which are consistent against...
computer science
37,968
Unsupervised deconvolution of dynamic imaging reveals intratumor vascular heterogeneity
stat.ML
Intratumor heterogeneity is often manifested by vascular compartments with distinct pharmacokinetics that cannot be resolved directly by in vivo dynamic imaging. We developed tissue-specific compartment modeling (TSCM), an unsupervised computational method of deconvolving dynamic imaging series from heterogeneous tumor...
computer science
37,969
Bayesian test of significance for conditional independence: The multinomial model
stat.CO
Conditional independence tests (CI tests) have received special attention lately in Machine Learning and Computational Intelligence related literature as an important indicator of the relationship among the variables used by their models. In the field of Probabilistic Graphical Models (PGM)--which includes Bayesian Net...
computer science
37,970
Local case-control sampling: Efficient subsampling in imbalanced data sets
stat.CO
For classification problems with significant class imbalance, subsampling can reduce computational costs at the price of inflated variance in estimating model parameters. We propose a method for subsampling efficiently for logistic regression by adjusting the class balance locally in feature space via an accept-reject ...
computer science
37,971
Supersparse Linear Integer Models for Interpretable Classification
stat.ML
Scoring systems are classification models that only require users to add, subtract and multiply a few meaningful numbers to make a prediction. These models are often used because they are practical and interpretable. In this paper, we introduce an off-the-shelf tool to create scoring systems that both accurate and inte...
computer science
37,972
Foundations of a Multi-way Spectral Clustering Framework for Hybrid Linear Modeling
stat.ML
The problem of Hybrid Linear Modeling (HLM) is to model and segment data using a mixture of affine subspaces. Different strategies have been proposed to solve this problem, however, rigorous analysis justifying their performance is missing. This paper suggests the Theoretical Spectral Curvature Clustering (TSCC) algori...
computer science
37,973
Gibbs posterior for variable selection in high-dimensional classification and data mining
stat.ME
In the popular approach of "Bayesian variable selection" (BVS), one uses prior and posterior distributions to select a subset of candidate variables to enter the model. A completely new direction will be considered here to study BVS with a Gibbs posterior originating in statistical mechanics. The Gibbs posterior is con...
computer science
37,974
Tuning parameter selection for penalized likelihood estimation of inverse covariance matrix
stat.ME
In a Gaussian graphical model, the conditional independence between two variables are characterized by the corresponding zero entries in the inverse covariance matrix. Maximum likelihood method using the smoothly clipped absolute deviation (SCAD) penalty (Fan and Li, 2001) and the adaptive LASSO penalty (Zou, 2006) hav...
computer science
37,975
High-dimensional Graphical Model Search with gRapHD R Package
stat.ML
This paper presents the R package gRapHD for efficient selection of high-dimensional undirected graphical models. The package provides tools for selecting trees, forests and decomposable models minimizing information criteria such as AIC or BIC, and for displaying the independence graphs of the models. It has also some...
computer science
37,976
On Ranking Senators By Their Votes
stat.ML
The problem of ranking a set of objects given some measure of similarity is one of the most basic in machine learning. Recently Agarwal proposed a method based on techniques in semi-supervised learning utilizing the graph Laplacian. In this work we consider a novel application of this technique to ranking binary choice...
computer science
37,977
A Nonconformity Approach to Model Selection for SVMs
stat.ML
We investigate the issue of model selection and the use of the nonconformity (strangeness) measure in batch learning. Using the nonconformity measure we propose a new training algorithm that helps avoid the need for Cross-Validation or Leave-One-Out model selection strategies. We provide a new generalisation error boun...
computer science
37,978
Computing p-values of LiNGAM outputs via Multiscale Bootstrap
stat.ML
Structural equation models and Bayesian networks have been widely used to study causal relationships between continuous variables. Recently, a non-Gaussian method called LiNGAM was proposed to discover such causal models and has been extended in various directions. An important problem with LiNGAM is that the results a...
computer science
37,979
Rumors in a Network: Who's the Culprit?
stat.ML
We provide a systematic study of the problem of finding the source of a rumor in a network. We model rumor spreading in a network with a variant of the popular SIR model and then construct an estimator for the rumor source. This estimator is based upon a novel topological quantity which we term \textbf{rumor centrality...
computer science
37,980
SpicyMKL
stat.ML
We propose a new optimization algorithm for Multiple Kernel Learning (MKL) called SpicyMKL, which is applicable to general convex loss functions and general types of regularization. The proposed SpicyMKL iteratively solves smooth minimization problems. Thus, there is no need of solving SVM, LP, or QP internally. SpicyM...
computer science
37,981
A Variational Bayes Approach to Decoding in a Phase-Uncertain Digital Receiver
stat.AP
This paper presents a Bayesian approach to symbol and phase inference in a phase-unsynchronized digital receiver. It primarily extends [Quinn 2011] to the multi-symbol case, using the variational Bayes (VB) approximation to deal with the combinatorial complexity of the phase inference in this case. The work provides a ...
computer science
37,982
Iteration Complexity of Randomized Block-Coordinate Descent Methods for Minimizing a Composite Function
math.OC
In this paper we develop a randomized block-coordinate descent method for minimizing the sum of a smooth and a simple nonsmooth block-separable convex function and prove that it obtains an $\epsilon$-accurate solution with probability at least $1-\rho$ in at most $O(\tfrac{n}{\epsilon} \log \tfrac{1}{\rho})$ iterations...
computer science
37,983
Multi-Task Averaging
stat.ML
We present a multi-task learning approach to jointly estimate the means of multiple independent data sets. The proposed multi-task averaging (MTA) algorithm results in a convex combination of the single-task maximum likelihood estimates. We derive the optimal minimum risk estimator and the minimax estimator, and show t...
computer science
37,984
Generalized Beta Mixtures of Gaussians
stat.ME
In recent years, a rich variety of shrinkage priors have been proposed that have great promise in addressing massive regression problems. In general, these new priors can be expressed as scale mixtures of normals, but have more complex forms and better properties than traditional Cauchy and double exponential priors. W...
computer science
37,985
Expectation-Propagation for Likelihood-Free Inference
stat.CO
Many models of interest in the natural and social sciences have no closed-form likelihood function, which means that they cannot be treated using the usual techniques of statistical inference. In the case where such models can be efficiently simulated, Bayesian inference is still possible thanks to the Approximate Baye...
computer science
37,986
Adaptive Independent Sticky MCMC algorithms
stat.CO
In this work, we introduce a novel class of adaptive Monte Carlo methods, called adaptive independent sticky MCMC algorithms, for efficient sampling from a generic target probability density function (pdf). The new class of algorithms employs adaptive non-parametric proposal densities which become closer and closer to ...
computer science
37,987
Joint modeling of multiple time series via the beta process with application to motion capture segmentation
stat.ME
We propose a Bayesian nonparametric approach to the problem of jointly modeling multiple related time series. Our model discovers a latent set of dynamical behaviors shared among the sequences, and segments each time series into regions defined by a subset of these behaviors. Using a beta process prior, the size of the...
computer science
37,988
Compound Poisson Processes, Latent Shrinkage Priors and Bayesian Nonconvex Penalization
stat.ML
In this paper we discuss Bayesian nonconvex penalization for sparse learning problems. We explore a nonparametric formulation for latent shrinkage parameters using subordinators which are one-dimensional L\'{e}vy processes. We particularly study a family of continuous compound Poisson subordinators and a family of disc...
computer science
37,989
Multiscale Inference for High-Frequency Data
stat.ME
This paper proposes a novel multiscale estimator for the integrated volatility of an Ito process, in the presence of market microstructure noise (observation error). The multiscale structure of the observed process is represented frequency-by-frequency and the concept of the multiscale ratio is introduced to quantify t...
computer science
37,990
New probabilistic interest measures for association rules
cs.DB
Mining association rules is an important technique for discovering meaningful patterns in transaction databases. Many different measures of interestingness have been proposed for association rules. However, these measures fail to take the probabilistic properties of the mined data into account. In this paper, we start ...
computer science
37,991
PDE-Foam - a probability-density estimation method using self-adapting phase-space binning
stat.ML
Probability Density Estimation (PDE) is a multivariate discrimination technique based on sampling signal and background densities defined by event samples from data or Monte-Carlo (MC) simulations in a multi-dimensional phase space. In this paper, we present a modification of the PDE method that uses a self-adapting bi...
computer science
37,992
Ultrahigh dimensional variable selection: beyond the linear model
stat.ME
Variable selection in high-dimensional space characterizes many contemporary problems in scientific discovery and decision making. Many frequently-used techniques are based on independence screening; examples include correlation ranking (Fan and Lv, 2008) or feature selection using a two-sample t-test in high-dimension...
computer science
37,993
Feature selection in omics prediction problems using cat scores and false nondiscovery rate control
stat.AP
We revisit the problem of feature selection in linear discriminant analysis (LDA), that is, when features are correlated. First, we introduce a pooled centroids formulation of the multiclass LDA predictor function, in which the relative weights of Mahalanobis-transformed predictors are given by correlation-adjusted $t$...
computer science
37,994
Regularization methods for learning incomplete matrices
stat.ML
We use convex relaxation techniques to provide a sequence of solutions to the matrix completion problem. Using the nuclear norm as a regularizer, we provide simple and very efficient algorithms for minimizing the reconstruction error subject to a bound on the nuclear norm. Our algorithm iteratively replaces the missing...
computer science
37,995
High Dimensional Nonlinear Learning using Local Coordinate Coding
stat.ML
This paper introduces a new method for semi-supervised learning on high dimensional nonlinear manifolds, which includes a phase of unsupervised basis learning and a phase of supervised function learning. The learned bases provide a set of anchor points to form a local coordinate system, such that each data point $x$ on...
computer science
37,996
Multiple Hypothesis Testing in Pattern Discovery
stat.ML
The problem of multiple hypothesis testing arises when there are more than one hypothesis to be tested simultaneously for statistical significance. This is a very common situation in many data mining applications. For instance, assessing simultaneously the significance of all frequent itemsets of a single dataset entai...
computer science
37,997
A path algorithm for the Fused Lasso Signal Approximator
stat.CO
The Lasso is a very well known penalized regression model, which adds an $L_{1}$ penalty with parameter $\lambda_{1}$ on the coefficients to the squared error loss function. The Fused Lasso extends this model by also putting an $L_{1}$ penalty with parameter $\lambda_{2}$ on the difference of neighboring coefficients, ...
computer science
37,998
BRAINSTORMING: Consensus Learning in Practice
stat.ML
We present here an introduction to Brainstorming approach, that was recently proposed as a consensus meta-learning technique, and used in several practical applications in bioinformatics and chemoinformatics. The consensus learning denotes heterogeneous theoretical classification method, where one trains an ensemble of...
computer science
37,999
Distance Dependent Chinese Restaurant Processes
stat.ML
We develop the distance dependent Chinese restaurant process (CRP), a flexible class of distributions over partitions that allows for non-exchangeability. This class can be used to model many kinds of dependencies between data in infinite clustering models, including dependencies across time or space. We examine the pr...
computer science
38,000
Fast Robust Methods for Singular State-Space Models
math.OC
State-space models are used in a wide range of time series analysis formulations. Kalman filtering and smoothing are work-horse algorithms in these settings. While classic algorithms assume Gaussian errors to simplify estimation, recent advances use a broader range of optimization formulations to allow outlier-robust e...
computer science
38,001
Aggregation using input-output trade-off
stat.ML
In this paper, we introduce a new learning strategy based on a seminal idea of Mojirsheibani (1999, 2000, 2002a, 2002b), who proposed a smart method for combining several classifiers, relying on a consensus notion. In many aggregation methods, the prediction for a new observation x is computed by building a linear or c...
computer science
38,002
Robust MCMC Sampling with Non-Gaussian and Hierarchical Priors in High Dimensions
stat.ME
A key problem in inference for high dimensional unknowns is the design of sampling algorithms whose performance scales favourably with the dimension of the unknown. A typical setting in which these problems arise is the area of Bayesian inverse problems. In such problems, which include graph-based learning, nonparametr...
computer science
38,003
A Stochastic Semismooth Newton Method for Nonsmooth Nonconvex Optimization
math.OC
In this work, we present a globalized stochastic semismooth Newton method for solving stochastic optimization problems involving smooth nonconvex and nonsmooth convex terms in the objective function. We assume that only noisy gradient and Hessian information of the smooth part of the objective function is available via...
computer science
38,004
Machine Learning Harnesses Molecular Dynamics to Discover New $μ$ Opioid Chemotypes
stat.ML
Computational chemists typically assay drug candidates by virtually screening compounds against crystal structures of a protein despite the fact that some targets, like the $\mu$ Opioid Receptor and other members of the GPCR family, traverse many non-crystallographic states. We discover new conformational states of $\m...
computer science
38,005
Coregionalised Locomotion Envelopes - A Qualitative Approach
stat.ML
'Sharing of statistical strength' is a phrase often employed in machine learning and signal processing. In sensor networks, for example, missing signals from certain sensors may be predicted by exploiting their correlation with observed signals acquired from other sensors. For humans, our hands move synchronously with ...
computer science
38,006
Coordination via predictive assistants from a game-theoretic view
cs.GT
We study machine learning-based assistants that support coordination between humans in congested facilities via congestion forecasts. In our theoretical analysis, we use game theory to study how an assistant's forecast that influences the outcome relates to Nash equilibria, and how they can be reached quickly in conges...
computer science
38,007
A Multi-Scheme Ensemble Using Coopetitive Soft-Gating With Application to Power Forecasting for Renewable Energy Generation
stat.AP
In this article, we propose a novel ensemble technique with a multi-scheme weighting based on a technique called coopetitive soft gating. This technique combines both, ensemble member competition and cooperation, in order to maximize the overall forecasting accuracy of the ensemble. The proposed algorithm combines the ...
computer science
38,008
Evaluating Conditional Cash Transfer Policies with Machine Learning Methods
econ.EM
This paper presents an out-of-sample prediction comparison between major machine learning models and the structural econometric model. Over the past decade, machine learning has established itself as a powerful tool in many prediction applications, but this approach is still not widely adopted in empirical economic stu...
computer science