Decision Tree Learning
Machine learning, Deutsche auction and repo haircuts - Risk.net
Watchdogs ask EC to delay repo haircut floors. It should come as no surprise that credit card companies supplement their revenues by selling real-time access to consumer transaction data – albeit aggregated and anonymised – and even less of a surprise that enterprising hedge funds have found a way to monetise it. This week, Risk.net reported how scrutinising data from millions of credit card transactions allowed a quant team to infer whether a company's sales are on the up or trending lower – without the need to wait for quarterly sales reports to be published. The analysis was delivered through a machine learning implementation of the random forest technique in which multitudes of decision trees combine to produce predictions. In this case, the algorithm enabled the quant shop to get an early warning on the health of companies whose options it held.
Machine Learning for Clinical Predictive Analytics
In this chapter, we provide a brief overview of applying machine learning techniques for clinical prediction tasks. We begin with a quick introduction to the concepts of machine learning and outline some of the most common machine learning algorithms. Next, we demonstrate how to apply the algorithms with appropriate toolkits to conduct machine learning experiments for clinical prediction tasks. The objectives of this chapter are to (1) understand the basics of machine learning techniques and the reasons behind why they are useful for solving clinical prediction problems, (2) understand the intuition behind some machine learning models, including regression, decision trees, and support vector machines, and (3) understand how to apply these models to clinical prediction problems using publicly available datasets via case studies.
On Education Decision Trees, Random Forests, AdaBoost & XGBoost in Python - all courses
Get a solid understanding of decision tree Understand the business scenarios where decision tree is applicable Tune a machine learning model's hyperparameters and evaluate its performance. Use Pandas DataFrames to manipulate data and make statistical computations. Use decision trees to make predictions Learn the advantage and disadvantages of the different algorithms Students will need to install Python and Anaconda software but we have a separate lecture to help you install the same You're looking for a complete Decision tree course that teaches you everything you need to create a Decision tree/ Random Forest/ XGBoost model in Python, right? You've found the right Decision Trees and tree based advanced techniques course! After completing this course you will be able to: Identify the business problem which can be solved using Decision tree/ Random Forest/ XGBoost of Machine Learning.
Uncovering Sociological Effect Heterogeneity using Machine Learning
Brand, Jennie E., Xu, Jiahui, Koch, Bernard, Geraldo, Pablo
Individuals do not respond uniformly to treatments, events, or interventions. Sociologists routinely partition samples into subgroups to explore how the effects of treatments vary by covariates like race, gender, and socioeconomic status. In so doing, analysts determine the key subpopulations based on theoretical priors. Data-driven discoveries are also routine, yet the analyses by which sociologists typically go about them are problematic and seldom move us beyond our expectations, and biases, to explore new meaningful subgroups. Emerging machine learning methods allow researchers to explore sources of variation that they may not have previously considered, or envisaged. In this paper, we use causal trees to recursively partition the sample and uncover sources of treatment effect heterogeneity. We use honest estimation, splitting the sample into a training sample to grow the tree and an estimation sample to estimate leaf-specific effects. Assessing a central topic in the social inequality literature, college effects on wages, we compare what we learn from conventional approaches for exploring variation in effects to causal trees. Given our use of observational data, we use leaf-specific matching and sensitivity analyses to address confounding and offer interpretations of effects based on observed and unobserved heterogeneity. We encourage researchers to follow similar practices in their work on variation in sociological effects.
8 Parameters to Qualify AI Solutions SalesChoice
One way could be to identify some of the most critical parameters to look for in any AI solution, and to rate/label them on a standard scale. Few such parameters are discussed below. Perhaps the community and policymakers can crystallize these further, and add to the list. Decision trees, Random forest, Gradient boosting, Monte Carlo, to name a few. The use of any one of these (say, Regression) in a solution can technically qualify it as AI-enabled, but it would not be very accurate or useful for a user. This has led to disillusionment among early AI users, while also giving rise to plethora of solutions and companies calling themselves AI.
Many Heads Are Better Than One: The Case For Ensemble Learning
"The interests of truth require a diversity of opinions." Banks and lenders are increasingly turning to AI and machine learning to automate their core functions and make more accurate predictions in credit underwriting and fraud detection. ML practitioners can take advantage of a growing number of modeling algorithms, such as simple decision trees, random forests, gradient boosting machines, deep neural networks, and support vector machines. Each method has its strengths and weaknesses, which is why it often makes sense to combine ML algorithms to provide even greater predictive performance than any single ML method could provide on its own. This method of combining algorithms is known as ensembling.
Toward Finding The Global Optimal of Adversarial Examples
Xiao, Zhenxin, Chang, Kai-Wei, Hsieh, Cho-Jui
Current machine learning models are vulnerable to adversarial examples (Goodfellow et al., 2014), we noticed that current state-of-the-art methods (Kurakin et al., 2016; Cheng et al., 2018) to attack a well-trained model often stuck in local optimal values. We conduct series of experiments on both white-box and black-box settings, and find out that by different initialization, the attack algorithm will finally converge to very different local optimals, suggesting the importance of careful and thorough search in the attack space. In this paper, we propose a general boosting algorithm that can help current attack to find a more global optimal example. Specifically, we search for the adversarial examples by starting from different points/directions, and in certain interval we adopt successive halving (Jamieson & Talwalkar, 2016) to cut down the searching directions that are not promising, and use Bayesian Optimization (Pelikan et al., 1999; Bergstra et al., 2011) to resample from the search space based on the knowledge obtained from past searches. We demonstrate that by applying our methods to state-of-the-art attack algorithms in both black-and white box setting, we can further reduce the distortion between the original image and adversarial sample about 10%-20%. By adopting dynamic successive halving, we can reduce the computation cost 5-10 times without harming the final result. We conduct experiments in models trained on MNIST or ImageNet and also try on decision tree models, these experiments suggest that our method is a general way to boost the performance of current adversarial attack methods.
LazyBum: Decision tree learning using lazy propositionalization
Schouterden, Jonas, Davis, Jesse, Blockeel, Hendrik
Propositionalization is the process of summarizing relational data into a tabular (attribute-value) format. The resulting table can next be used by any propositional learner. This approach makes it possible to apply a wide variety of learning methods to relational data. However, the transformation from relational to propositional format is generally not lossless: different relational structures may be mapped onto the same feature vector. At the same time, features may be introduced that are not needed for the learning task at hand. In general, it is hard to define a feature space that contains all and only those features that are needed for the learning task. This paper presents LazyBum, a system that can be considered a lazy version of the recently proposed OneBM method for propositionalization. LazyBum interleaves OneBM's feature construction method with a decision tree learner. This learner both uses and guides the propositionalization process. It indicates when and where to look for new features. This approach is similar to what has elsewhere been called dynamic propositionalization. In an experimental comparison with the original OneBM and with two other recently proposed propositionalization methods (nFOIL and MODL, which respectively perform dynamic and static propositionalization), LazyBum achieves a comparable accuracy with a lower execution time on most of the datasets.
Towards Safe Machine Learning for CPS: Infer Uncertainty from Training Data
Machine learning (ML) techniques are increasingly applied to decision-making and control problems in Cyber-Physical Systems among which many are safety-critical, e.g., chemical plants, robotics, autonomous vehicles. Despite the significant benefits brought by ML techniques, they also raise additional safety issues because 1) most expressive and powerful ML models are not transparent and behave as a black box and 2) the training data which plays a crucial role in ML safety is usually incomplete. An important technique to achieve safety for ML models is "Safe Fail", i.e., a model selects a reject option and applies the backup solution, a traditional controller or a human operator for example, when it has low confidence in a prediction. Data-driven models produced by ML algorithms learn from training data, and hence they are only as good as the examples they have learnt. As pointed in [17], ML models work well in the "training space" (i.e., feature space with sufficient training data), but they could not extrapolate beyond the training space. As observed in many previous studies, a feature space that lacks training data generally has a much higher error rate than the one that contains sufficient training samples [31]. Therefore, it is essential to identify the training space and avoid extrapolating beyond the training space. In this paper, we propose an efficient Feature Space Partitioning Tree (FSPT) to address this problem. Using experiments, we also show that, a strong relationship exists between model performance and FSPT score.
Trump administration updates AI strategy, with emphasis on transparency, data integrity
In its update to its National Artificial Intelligence Research And Development Strategic Plan, the White House's Office of Science and Technology Policy has set new objectives for federal AI research. WHY IT MATTERS The strategic plan boils down to eight strategies for how government can better enable development of safe and effective AI and machine learning technologies for healthcare and other industries. The 50-page document takes special interest in ensuring that data used to power AI is trustworthy and that the algorithms used to process it are understandable – not least in healthcare. "A key research challenge is increasing the'explainability' or ''transparency' of AI," according to the report. "Many algorithms, including those based on deep learning, are opaque to users, with few existing mechanisms for explaining their results. This is especially problematic for domains such as healthcare, where doctors need explanations to justify a particular diagnosis or a course of treatment. AI techniques such as decision-tree induction provide built-in explanations but are generally less accurate. Thus, researchers must develop systems that are transparent, and intrinsically capable of explaining the reasons for their results to users."