Ensemble Learning
Techinfoplace Softwares Pvt Ltd.
Problem Statement A target marketing campaign for a bank was undertaken to identify a segment of customers who are likely to respond to an insurance product. Here, the target variable is whether or not the customers bought insurance product and it depends on factors like Product usage in three months, demographics, transaction patterns as like deposit amount, checking account, a branch of the bank, Residential information (like urban, rural) and so on.
Performance and Interpretability Comparisons of Supervised Machine Learning Algorithms: An Empirical Study
Liu, Alice J., Mukherjee, Arpita, Hu, Linwei, Chen, Jie, Nair, Vijayan N.
This paper compares the performances of three supervised machine learning algorithms in terms of predictive ability and model interpretation on structured or tabular data. The algorithms considered were scikit-learn implementations of extreme gradient boosting machines (XGB) and random forests (RFs), and feedforward neural networks (FFNNs) from TensorFlow. The paper is organized in a findings-based manner, with each section providing general conclusions supported by empirical results from simulation studies that cover a wide range of model complexity and correlation structures among predictors. We considered both continuous and binary responses of different sample sizes. Overall, XGB and FFNNs were competitive, with FFNNs showing better performance in smooth models and tree-based boosting algorithms performing better in non-smooth models. This conclusion held generally for predictive performance, identification of important variables, and determining correct input-output relationships as measured by partial dependence plots (PDPs). FFNNs generally had less over-fitting, as measured by the difference in performance between training and testing datasets. However, the difference with XGB was often small. RFs did not perform well in general, confirming the findings in the literature. All models exhibited different degrees of bias seen in PDPs, but the bias was especially problematic for RFs. The extent of the biases varied with correlation among predictors, response type, and data set sample size. In general, tree-based models tended to over-regularize the fitted model in the tails of predictor distributions. Finally, as to be expected, performances were better for continuous responses compared to binary data and with larger samples.
Pruned Random Forests for Effective and Efficient Financial Data Analytics
It is evident that Machine Learning (ML) has touched all walks of our lives! From checking the weather forecast to applying for a loan or a credit card, ML is used in almost every aspect of our daily life. In this chapter, ML is explored in terms of algorithms and applications. Special consideration is given to ML applications in the financial data analytics domain including stock market analysis, fraud detection in financial transactions, credit risk analysis, loan defaulting rate analysis, and profit–loss analysis. The chapter establishes the significance of Random Forests as an effective machine learning method for a wide variety of financial applications.
A study of tree-based methods and their combination
With the increase of data volume and the continuous development in deep learning, although more and more traditional machine learning techniques are outperformed by artificial neural networks, tree-based methods are still popular. Random forest (Breiman, 2001) is commonly used as a benchmark to evaluate the performance of nonparametric models, while XGBoost (Chen and Guestrin, 2016) performs well in Kaggle competitions and often competes with artificial neural networks. Also, instead of relying on a specific method, people prefer to make decisions based on a combination of multiple models, which shows a better performance than a single one. Therefore, identifying the importance of each model by weights assignment is critical.
Identification of feasible pathway information for c-di-GMP binding proteins in cellulose production
Hassan, Syeda Sakira, Mangayil, Rahul, Aho, Tommi, Yli-Harja, Olli, Karp, Matti
In this paper, we utilize a machine learning approach to identify the significant pathways for c-di-GMP signaling proteins. The dataset involves gene counts from 12 pathways and 5 essential c-di-GMP binding domains for 1024 bacterial genomes. Two novel approaches, Least absolute shrinkage and selection operator (Lasso) and Random forests, have been applied for analyzing and modeling the dataset. Both approaches show that bacterial chemotaxis is the most essential pathway for c-di-GMP encoding domains. Though popular for feature selection, the strong regularization of Lasso method fails to associate any pathway to MshE domain. Results from the analysis may help to understand and emphasize the supporting pathways involved in bacterial cellulose production. These findings demonstrate the need for a chassis to restrict the behavior or functionality by deactivating the selective pathways in cellulose production.
Confidence Band Estimation for Survival Random Forests
Formentini, Sarah Elizabeth, Liang, Wei, Zhu, Ruoqing
Survival random forest is a popular machine learning tool for modeling censored survival data. However, there is currently no statistically valid and computationally feasible approach for estimating its confidence band. This paper proposes an unbiased confidence band estimation by extending recent developments in infinite-order incomplete U-statistics. The idea is to estimate the variance-covariance matrix of the cumulative hazard function prediction on a grid of time points. We then generate the confidence band by viewing the cumulative hazard function estimation as a Gaussian process whose distribution can be approximated through simulation. This approach is computationally easy to implement when the subsampling size of a tree is no larger than half of the total training sample size. Numerical studies show that our proposed method accurately estimates the confidence band and achieves desired coverage rate. We apply this method to veterans' administration lung cancer data.
Bojan Tunguz, Ph.D. on LinkedIn: #MachineLerning #DeepLearning #DataScience
Recently I came across this incredible survey paper on the use of neural networks for tabular data. After going through it carefully, I can confidently say that it's thus far THE best paper on the subject. It goes into depth of all the main issues that have stymied the use of NNs in this domain. The paper is very thoughtful, systematic, and fairly thorough. Despite what the authors claim, though, it is not the first paper on the topic, but it goes well beyond many recent papers on the subjects. It also doesn't have as an exhaustive set of datasets that it uses as some of the other papers.
Machine Learning-Enabled IoT Security: Open Issues and Challenges Under Advanced Persistent Threats
Chen, Zhiyan, Liu, Jinxin, Shen, Yu, Simsek, Murat, Kantarci, Burak, Mouftah, Hussein T., Djukic, Petar
Despite its technological benefits, Internet of Things (IoT) has cyber weaknesses due to the vulnerabilities in the wireless medium. Machine learning (ML)-based methods are widely used against cyber threats in IoT networks with promising performance. Advanced persistent threat (APT) is prominent for cybercriminals to compromise networks, and it is crucial to long-term and harmful characteristics. However, it is difficult to apply ML-based approaches to identify APT attacks to obtain a promising detection performance due to an extremely small percentage among normal traffic. There are limited surveys to fully investigate APT attacks in IoT networks due to the lack of public datasets with all types of APT attacks. It is worth to bridge the state-of-the-art in network attack detection with APT attack detection in a comprehensive review article. This survey article reviews the security challenges in IoT networks and presents the well-known attacks, APT attacks, and threat models in IoT systems. Meanwhile, signature-based, anomaly-based, and hybrid intrusion detection systems are summarized for IoT networks. The article highlights statistical insights regarding frequently applied ML-based methods against network intrusion alongside the number of attacks types detected. Finally, open issues and challenges for common network intrusion and APT attacks are presented for future research.
Distributional Gradient Boosting Machines
März, Alexander, Kneib, Thomas
We present a unified probabilistic gradient boosting framework for regression tasks that models and predicts the entire conditional distribution of a univariate response variable as a function of covariates. Our likelihood-based approach allows us to either model all conditional moments of a parametric distribution, or to approximate the conditional cumulative distribution function via Normalizing Flows. As underlying computational backbones, our framework is based on XGBoost and LightGBM. Modelling and predicting the entire conditional distribution greatly enhances existing tree-based gradient boosting implementations, as it allows to create probabilistic forecasts from which prediction intervals and quantiles of interest can be derived. Empirical results show that our framework achieves state-of-the-art forecast accuracy.