good feature
Using Noise to Infer Aspects of Simplicity Without Learning Zachery Boner 1 Harry Chen
Noise in data significantly influences decision-making in the data science process. In fact, it has been shown that noise in data generation processes leads practitioners to find simpler models. However, an open question still remains: what is the degree of model simplification we can expect under different noise levels? In this work, we address this question by investigating the relationship between the amount of noise and model simplicity across various hypothesis spaces, focusing on decision trees and linear models. We formally show that noise acts as an implicit regularizer for several different noise models. Furthermore, we prove that Rashomon sets (sets of near-optimal models) constructed with noisy data tend to contain simpler models than corresponding Rashomon sets with non-noisy data. Additionally, we show that noise expands the set of "good" features and consequently enlarges the set of models that use at least one good feature. Our work offers theoretical guarantees and practical insights for practitioners and policymakers on whether simple-yet-accurate machine learning models are likely to exist, based on knowledge of noise levels in the data generation process.
Using Noise to Infer Aspects of Simplicity Without Learning Zachery Boner 1 Harry Chen
Noise in data significantly influences decision-making in the data science process. In fact, it has been shown that noise in data generation processes leads practitioners to find simpler models. However, an open question still remains: what is the degree of model simplification we can expect under different noise levels? In this work, we address this question by investigating the relationship between the amount of noise and model simplicity across various hypothesis spaces, focusing on decision trees and linear models. We formally show that noise acts as an implicit regularizer for several different noise models. Furthermore, we prove that Rashomon sets (sets of near-optimal models) constructed with noisy data tend to contain simpler models than corresponding Rashomon sets with non-noisy data. Additionally, we show that noise expands the set of "good" features and consequently enlarges the set of models that use at least one good feature. Our work offers theoretical guarantees and practical insights for practitioners and policymakers on whether simple-yet-accurate machine learning models are likely to exist, based on knowledge of noise levels in the data generation process.
On the choice of the non-trainable internal weights in random feature maps
Mandal, Pinak, Gottwald, Georg A.
The computationally cheap machine learning architecture of random feature maps can be viewed as a single-layer feedforward network in which the weights of the hidden layer are random but fixed and only the outer weights are learned via linear regression. The internal weights are typically chosen from a prescribed distribution. The choice of the internal weights significantly impacts the accuracy of random feature maps. We address here the task of how to best select the internal weights. In particular, we consider the forecasting problem whereby random feature maps are used to learn a one-step propagator map for a dynamical system. We provide a computationally cheap hit-and-run algorithm to select good internal weights which lead to good forecasting skill. We show that the number of good features is the main factor controlling the forecasting skill of random feature maps and acts as an effective feature dimension. Lastly, we compare random feature maps with single-layer feedforward neural networks in which the internal weights are now learned using gradient descent. We find that random feature maps have superior forecasting capabilities whilst having several orders of magnitude lower computational cost.
Saliency Guided Adversarial Training for Learning Generalizable Features with Applications to Medical Imaging Classification System
Li, Xin, Qiang, Yao, Li, Chengyin, Liu, Sijia, Zhu, Dongxiao
Nevertheless, the performance degradation on OOD test sets remains a salient problem (Shao et al., 2020). One observation This work tackles a central machine learning is that the current approach introduces a nearly ideal problem of performance degradation on out-ofdistribution scenario for DNN to learn spurious shortcuts or non-relevant (OOD) test sets. The problem is particularly features (Geirhos et al., 2020) that do not exist in OOD test salient in medical imaging based diagnosis sets. In medical imaging systems, the problem becomes system that appears to be accurate but fails even more salient due to the significant distribution shift when tested in new hospitals/datasets. Recent between imaging data sets acquired from different hospitals, studies indicate the system might learn shortcut populations, and time periods. As a result, the AI imaging and non-relevant features instead of generalizable system that is seemingly effective on training sets often does features, so-called'good features'. We hypothesize not generalize well to new hospitals or data sets (DeGrave that adversarial training can eliminate shortcut et al., 2021). Fortunately, in the relatively closed medical features whereas saliency guided training can imaging environment, we are not so much concerned about filter out non-relevant features; both are nuisance adversarial OOD test sets. Instead, we consider how to features accounting for the performance degradation leverage adversarial IID data sets for learning good features.
Bye-bye Python. Hello Julia!
Python's popularity is still backed by a rock-solid community of computer scientists, data scientists and AI specialists. But if you've ever been at a dinner table with these people, you also know how much they rant about the weaknesses of Python. From being slow to requiring excessive testing, to producing runtime errors despite prior testing -- there's enough to be pissed off about. Which is why more and more programmers are adopting other languages -- the top players being Julia, Go, and Rust. Julia is great for mathematical and technical tasks, while Go is awesome for modular programs, and Rust is the top choice for systems programming.
OpenCV #013 Harris Corner Detector - Theory Master Data Science
Highlights: In this post we will learn about Harris Corner Detector and how can we use this method to detect corners. We will give a brief overview how this method works, but we'll not go so seriously with mathematics. What is Harris Corner Detector? In many computer vision and machine learning applications we need some feature points which we will track or which will assist us to compare and detect objects or scenes. We will explain that corners are in particular interesting for detection both visually and mathematically.
On the Consistency of Optimal Bayesian Feature Selection in the Presence of Correlations
pour, Ali Foroughi, Dalton, Lori A.
Optimal Bayesian feature selection (OBFS) is a multivariat e supervised screening method designed from the ground up for bioma rker discovery. In this work, we prove that Gaussian OBFS is strongly consisten t under mild conditions, and provide rates of convergence for key posteriors i n the framework. These results are of enormous importance, since they identify pre cisely what features are selected by OBFS asymptotically, characterize the relativ e rates of convergence for posteriors on different types of features, provide condi tions that guarantee convergence, justify the use of OBFS when its internal assum ptions are invalid, and set the stage for understanding the asymptotic behavior of other algorithms based on the OBFS framework.
Customer churn classification using predictive machine learning models - WebSystemer.no
Metis Data Science Bootcamp has been rigorous, and this is my third project. The goal is to predict customer churn in a Telecommunication company. Customer attrition, customer turnover, or customer defection -- they all refer to the loss of clients or customers, ie, churn. This can be due to voluntary reasons (by choice) or involuntary reasons (for example relocation). In this article, we will explore 8 predictive analytic models to assess customers' propensity or risk to churn.
Theory of Optimal Bayesian Feature Filtering
pour, Ali Foroughi, Dalton, Lori A.
Optimal Bayesian feature filtering (OBF) is a supervised screening method designed for biomarker discovery. In this article, we prove two major theoretical properties of OBF. First, optimal Bayesian feature selection under a general family of Bayesian models reduces to filtering if and only if the underlying Bayesian model assumes all features are mutually independent. Therefore, OBF is optimal if and only if one assumes all features are mutually independent, and OBF is the only filter method that is optimal under at least one model in the general Bayesian framework. Second, OBF under independent Gaussian models is consistent under very mild conditions, including cases where the data is non-Gaussian with correlated features. This result provides conditions where OBF is guaranteed to identify the correct feature set given enough data, and it justifies the use of OBF in non-design settings where its assumptions are invalid.
Natural Language Processing(NLP) for Machine Learning
In this article well be learning about Natural Language Processing(NLP) which can help computers analyze text easily i.e detect spam emails, autocorrect. We'll see how NLP tasks are carried out for understanding human language. NLP is a field in machine learning with the ability of a computer to understand, analyze, manipulate, and potentially generate human language. Rather than building all tools from scratch, NLTK provides all common NLP Tasks. This should work in most cases.