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 Statistical Learning


Elastic Coupled Co-clustering for Single-Cell Genomic Data

arXiv.org Machine Learning

The recent advances in single-cell technologies have enabled us to profile genomic features at unprecedented resolution and data sets from multiple domains are available, including data sets that profile different types of genomic features and data sets that profile the same type of genomic features across different species. These data sets typically have different powers in identifying the unknown cell types through clustering, and data integration can potentially lead to a better performance of clustering algorithms. In this work, we formulate the problem in an unsupervised transfer learning framework, which utilizes knowledge learned from auxiliary data set to improve the clustering performance of target data set. The degree of shared information among the target and auxiliary data sets can vary, and their distributions can also be different. To address these challenges, we propose an elastic coupled co-clustering based transfer learning algorithm, by elastically propagating clustering knowledge obtained from the auxiliary data set to the target data set. Implementation on single-cell genomic data sets shows that our algorithm greatly improves clustering performance over the traditional learning algorithms. The source code and data sets are available at https://github.com/cuhklinlab/elasticC3.


Iterative Pre-Conditioning to Expedite the Gradient-Descent Method

arXiv.org Machine Learning

This paper considers the problem of multi-agent distributed optimization. In this problem, there are multiple agents in the system, and each agent only knows its local cost function. The objective for the agents is to collectively compute a common minimum of the aggregate of all their local cost functions. In principle, this problem is solvable using a distributed variant of the traditional gradient-descent method, which is an iterative method. However, the speed of convergence of the traditional gradient-descent method is highly influenced by the conditioning of the optimization problem being solved. Specifically, the method requires a large number of iterations to converge to a solution if the optimization problem is ill-conditioned. In this paper, we propose an iterative pre-conditioning approach that can significantly attenuate the influence of the problem's conditioning on the convergence-speed of the gradient-descent method. The proposed pre-conditioning approach can be easily implemented in distributed systems and has minimal computation and communication overhead. For now, we only consider a specific distributed optimization problem wherein the individual local cost functions of the agents are quadratic. Besides the theoretical guarantees, the improved convergence speed of our approach is demonstrated through experiments on a real data-set.


r/datascience - :)

#artificialintelligence

I know this is a joke, but are there really people out there using linear regression and calling it "machine learning"? Edit: y'all are right that linear regression is certainly a form of statistical learning. I think the main reason I instinctively think of it as being "not machine learning" is that it has a simple closed-form solution--so the "machine" part of statistical learning with linear regression is unnecessary. The same can't be said for a lot of other algorithms that are more comfortably referred to as "machine learning", you know?


A Top Machine Learning Algorithm Explained: Support Vector Machines (SVM) - KDnuggets

#artificialintelligence

By Clare Liu, Data Scientist at fintech industry, based in HK. One of the most prevailing and exciting supervised learning models with associated learning algorithms that analyse data and recognise patterns is Support Vector Machines (SVMs). It is used for solving both regression and classification problems. However, it is mostly used in solving classification problems. SVMs were first introduced by B.E. Boser et al. in 1992 and has become popular due to success in handwritten digit recognition in 1994.


Machine learning with Python: An introduction

#artificialintelligence

Machine learning is one of our most important technologies for the future. Self-driving cars, voice-controlled speakers, and face detection software all are built on machine learning technologies and frameworks. As a software developer you may wonder how this will impact your daily work, including the tools and frameworks you should learn. If you're reading this article, my guess is you've already decided to learn more about machine learning. In my previous article, "Machine Learning for Java developers," I introduced Java developers to setting up a machine learning algorithm and developing a simple prediction function in Java.


Machine learning with Python: An introduction

#artificialintelligence

Machine learning is one of our most important technologies for the future. Self-driving cars, voice-controlled speakers, and face detection software all are built on machine learning technologies and frameworks. As a software developer you may wonder how this will impact your daily work, including the tools and frameworks you should learn. If you're reading this article, my guess is you've already decided to learn more about machine learning. In my previous article, "Machine Learning for Java developers," I introduced Java developers to setting up a machine learning algorithm and developing a simple prediction function in Java.


Distributed function estimation: adaptation using minimal communication

arXiv.org Machine Learning

Distributed methods have attracted a lot of attention in the statistics and machine learning communities recently. There are several reasons for this, the most prominent ones being that they provide a way of dealing with large datasets and with privacy considerations. The theoretical literature on distributed methods is still rather minimal at the moment. A number of papers have recently investigated fundamental performance limits in distributed models, in particular pointing out issues that occur in high-dimensional or nonparametric problems, see for instance [1, 2, 4, 8, 16, 17, 21, 24, 27]. For example, optimal rates in distributed function estimation depend on the amount of communication that is allowed, and the relation of that amount with the regularity of the unknown function. The lower bounds obtained in [25] and [28] and the subsequent adaptation results in [25] show that in particular, automatically adapting to the smoothness of the unknown function is a complicated issue in communication restricted distributed settings. In the present paper we study this problem from a different, we think relevant and interesting perspective, not restricting communication a priori, but asking for rate-optimal procedures that require minimal communication.


Federated Residual Learning

arXiv.org Machine Learning

We study a new form of federated learning where the clients train personalized local models and make predictions jointly with the server-side shared model. Using this new federated learning framework, the complexity of the central shared model can be minimized while still gaining all the performance benefits that joint training provides. Our framework is robust to data heterogeneity, addressing the slow convergence problem traditional federated learning methods face when the data is non-i.i.d. across clients. We test the theory empirically and find substantial performance gains over baselines.


An End-to-End Approach for Recognition of Modern and Historical Handwritten Numeral Strings

arXiv.org Machine Learning

An end-to-end solution for handwritten numeral string recognition is proposed, in which the numeral string is considered as composed of objects automatically detected and recognized by a YoLo-based model. The main contribution of this paper is to avoid heuristic-based methods for string preprocessing and segmentation, the need for task-oriented classifiers, and also the use of specific constraints related to the string length. A robust experimental protocol based on several numeral string datasets, including one composed of historical documents, has shown that the proposed method is a feasible end-to-end solution for numeral string recognition. Besides, it reduces the complexity of the string recognition task considerably since it drops out classical steps, in special preprocessing, segmentation, and a set of classifiers devoted to strings with a specific length.


Seeing The Whole Patient: Using Multi-Label Medical Text Classification Techniques to Enhance Predictions of Medical Codes

arXiv.org Machine Learning

Machine learning-based multi-label medical text classifications can be used to enhance the understanding of the human body and aid the need for patient care. We present a broad study on clinical natural language processing techniques to maximise a feature representing text when predicting medical codes on patients with multi-morbidity. We present results of multi-label medical text classification problems with 18, 50 and 155 labels. We compare several variations to embeddings, text tagging, and pre-processing. For imbalanced data we show that labels which occur infrequently, benefit the most from additional features incorporated in embeddings. We also show that high dimensional embeddings pre-trained using health-related data present a significant improvement in a multi-label setting, similarly to the way they improve performance for binary classification. High dimensional embeddings from this research are made available for public use.