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Forecasting the evolution of complex systems is one of the grand challenges of modern data science. The fundamental difficulty lies in understanding the structure of the observed stochastic process. In this paper, we show that every…

Statistics Theory · Mathematics 2020-01-01 Xiucai Ding , Zhou Zhou

Designing a covariance function that represents the underlying correlation is a crucial step in modeling complex natural systems, such as climate models. Geospatial datasets at a global scale usually suffer from non-stationarity and…

Machine Learning · Statistics 2015-07-10 Chintan A. Dalal , Vladimir Pavlovic , Robert E. Kopp

Adjusting for covariates is a well established method to estimate the total causal effect of an exposure variable on an outcome of interest. Depending on the causal structure of the mechanism under study there may be different adjustment…

Statistics Theory · Mathematics 2021-04-27 Jack Kuipers , Giusi Moffa

Imbalance in covariate distributions leads to biased estimates of causal effects. Weighting methods attempt to correct this imbalance but rely on specifying models for the treatment assignment mechanism, which is unknown in observational…

Methodology · Statistics 2022-05-13 Eric Dunipace

Gaussian Processes are used in many applications to model spatial phenomena. Within this context, a key issue is to decide the set of locations where to take measurements so as to obtain a better approximation of the underlying function.…

Emerging Technologies · Computer Science 2019-01-31 Lorenzo Bottarelli , Alessandro Farinelli

Estimating covariances between financial assets plays an important role in risk management. In practice, when the sample size is small compared to the number of variables, the empirical estimate is known to be very unstable. Here, we…

Computational Engineering, Finance, and Science · Computer Science 2019-04-19 Rajbir-Singh Nirwan , Nils Bertschinger

Marginal structural models are a popular method for estimating causal effects in the presence of time-varying exposures. In spite of their popularity, no scalable non-parametric estimator exist for marginal structural models with…

Methodology · Statistics 2024-09-30 Axel Martin , Michele Santacatterina , Iván Díaz

The Partial Area Under the ROC Curve (PAUC), typically including One-way Partial AUC (OPAUC) and Two-way Partial AUC (TPAUC), measures the average performance of a binary classifier within a specific false positive rate and/or true positive…

Machine Learning · Computer Science 2022-10-12 Huiyang Shao , Qianqian Xu , Zhiyong Yang , Shilong Bao , Qingming Huang

This paper presents methods which are aimed at finding approximations to missing data in a dataset by using optimization algorithms to optimize the network parameters after which prediction and classification tasks can be performed. The…

Neural and Evolutionary Computing · Computer Science 2014-03-24 Collins Leke , Bhekisipho Twala , T. Marwala

We introduce a new interpretation of sparse variational approximations for Gaussian processes using inducing points, which can lead to more scalable algorithms than previous methods. It is based on decomposing a Gaussian process as a sum of…

Machine Learning · Statistics 2024-02-27 Jiaxin Shi , Michalis K. Titsias , Andriy Mnih

Generalized linear models are a popular tool in applied statistics, with their maximum likelihood estimators enjoying asymptotic Gaussianity and efficiency. As all models are wrong, it is desirable to understand these estimators' behaviours…

Methodology · Statistics 2024-12-10 Elliot H. Young , Rajen D. Shah

Generalized additive partial linear models (GAPLMs) are appealing for model interpretation and prediction. However, for GAPLMs, the covariates and the degree of smoothing in the nonparametric parts are often difficult to determine in…

Methodology · Statistics 2022-12-06 Ze Chen , Jun Liao , Wangli Xu , Yuhong Yang

In this paper, we provide a mathematical framework for improving generalization in a class of learning problems which is related to point estimations for modeling of high-dimensional nonlinear functions. In particular, we consider a…

Optimization and Control · Mathematics 2024-12-13 Getachew K. Befekadu

Local Stochastic Gradient Descent (SGD) with periodic model averaging (FedAvg) is a foundational algorithm in Federated Learning. The algorithm independently runs SGD on multiple workers and periodically averages the model across all the…

Machine Learning · Computer Science 2022-01-12 Sunwoo Lee , Anit Kumar Sahu , Chaoyang He , Salman Avestimehr

In the classic measurement error framework, covariates are contaminated by independent additive noise. This paper considers parameter estimation in such a linear errors-in-variables model where the unknown measurement error distribution is…

Methodology · Statistics 2023-10-24 Linh H. Nghiem , Cornelis J. Potgieter

Observations which are realizations from some continuous process are frequent in sciences, engineering, economics, and other fields. We consider linear models, with possible random effects, where the responses are random functions in a…

Statistics Theory · Mathematics 2016-11-30 Giacomo Aletti , Caterina May , Chiara Tommasi

Sequential minimum optimization is a machine-learning global search training algorithm. It is applicable when the functional dependence of the cost function on a tunable parameter given the other parameters can be cheaply determined. This…

Quantum Physics · Physics 2023-03-03 Wojciech Roga , Takafumi Ono , Masahiro Takeoka

We study the clustering task under anisotropic Gaussian Mixture Models where the covariance matrices from different clusters are unknown and are not necessarily the identical matrix. We characterize the dependence of signal-to-noise ratios…

Statistics Theory · Mathematics 2021-01-19 Xin Chen , Anderson Y. Zhang

Unobserved confounding is one of the main challenges when estimating causal effects. We propose a causal reduction method that, given a causal model, replaces an arbitrary number of possibly high-dimensional latent confounders with a single…

Machine Learning · Statistics 2023-02-24 Maximilian Ilse , Patrick Forré , Max Welling , Joris M. Mooij

Estimating the generalization error (GE) of machine learning models is fundamental, with resampling methods being the most common approach. However, in non-standard settings, particularly those where observations are not independently and…