Statistical Learning
Profiting from Python & Machine Learning in the Financial Markets
I finally beat the S&P 500 by 10%. This might not sound like much but when we're dealing with large amounts of capital and with good liquidity, the profits are pretty sweet for a hedge fund. More aggressive approaches have resulted in much higher returns. It all started after I read a paper by Gur Huberman titled "Contagious Speculation and a Cure for Cancer: A Non-Event that Made Stock Prices Soar," (with Tomer Regev, Journal of Finance, February 2001, Vol. "A Sunday New York Times article on a potential development of new cancer-curing drugs caused EntreMed's stock price to rise from 12.063 at the Friday close, to open at 85 and close near 52 on Monday. It closed above 30 in the three following weeks. The enthusiasm spilled over to other biotechnology stocks. The potential breakthrough in cancer research already had been reported, however, in the journal Nature, and in various popular newspapers including the Times! Thus, enthusiastic public attention induced a permanent rise in share prices, even though no genuinely new information had been presented."
Some Essential Hacks and Tricks for Machine Learning with Python
It's never been easier to get started with machine learning. In addition to structured MOOCs, there is also a huge number of incredible, free resources available around the web. Familiarity and moderate expertise in at least one high-level programming language is useful for beginners in machine learning. Unless you are a Ph.D. researcher working on a purely theoretical proof of some complex algorithm, you are expected to mostly use the existing machine learning algorithms and apply them in solving novel problems. This requires you to put on a programming hat.
Top 5 Data Science and Machine Learning Courses for Programmers
Arthur Samuel first coined machine learning in the year 1959. It is the field of computer science that uses statistical techniques. It gives computer systems the ability to learn with data without being explicitly programmed. Data science, on the other hand, is an interdisciplinary field of scientific methods, processes, algorithms, and systems that extract knowledge from data in various forms, either structured or unstructured, similar to data mining. The development of these two made research a lot easier.
How to become a machine learning and deep learning engineer?
Here's a list of good books, with a brief explanation about them, which you can read to learn the essentials of machine learning: This book is the most expensive(from science perspective) and valuable book in machine learning world. It's so complete and it cover almost all aspects of machine learning. The book is written in an informal, accessible style, complete with pseudo-code for the most important algorithms. All topics are copiously illustrated with color images and worked examples drawn from such application domains as biology, text processing, computer vision, and robotics. But it's disadvantages are, First, it's too long.
SMOTE for Learning from Imbalanced Data: Progress and Challenges, Marking the 15-year Anniversary
Fernandez, Alberto, Garcia, Salvador, Herrera, Francisco, Chawla, Nitesh V.
The Synthetic Minority Oversampling Technique (SMOTE) preprocessing algorithm is considered "de facto" standard in the framework of learning from imbalanced data. This is due to its simplicity in the design of the procedure, as well as its robustness when applied to different type of problems. Since its publication in 2002, SMOTE has proven successful in a variety of applications from several different domains. SMOTE has also inspired several approaches to counter the issue of class imbalance, and has also significantly contributed to new supervised learning paradigms, including multilabel classification, incremental learning, semi-supervised learning, multi-instance learning, among others. It is standard benchmark for learning from imbalanced data. It is also featured in a number of different software packages -- from open source to commercial. In this paper, marking the fifteen year anniversary of SMOTE, we reflect on the SMOTE journey, discuss the current state of affairs with SMOTE, its applications, and also identify the next set of challenges to extend SMOTE for Big Data problems.
Streaming Active Learning Strategies for Real-Life Credit Card Fraud Detection: Assessment and Visualization
Carcillo, Fabirzio, Borgne, Yann-Aรซl Le, Caelen, Olivier, Bontempi, Gianluca
Some of them are related to the data distribution, notably the class imbalance of the training set (many more genuine transactions than fraudulent ones), the non-stationarity of the phenomenon (due to changes in the behavior of customers as well as in fraudsters), the large dimensionality and the overlapping classes (while fraudsters try to emulate cardholders behavior, genuine behaviors of cardholders might look strange or anomalous). The labeling process is constrained, as every day human investigators may contact only a small number of cardholders associated with the riskiest transactions and obtain the class (fraud or genuine) of the related transactions. The high cost of human labour, for assessing the transaction labels, leads to the labeling bottleneck [2]. In this context, an automatic Fraud Detection System (FDS) should support the activity of the investigators by letting them focus on the transactions with the highest fraud probability. From the perspective of the transactional service company, this is crucial in order to reduce the costs of the investigation activity and to retain the customer confidence. From a machine learning perspective it is important to keep an adequate balance between exploitation and exploration, i.e. between the short-term needs of providing good alerts to investigators, and the long-term goal of maintaining a high accuracy of the system (e.g. in the presence of concept drift). The issue of labeling the most informative data by minimizing the cost has been extensively addressed by active learning which can be considered as a specific instance of semi-supervised learning [8, 41], the domain studying how unlabeled and labeled data can both contribute to 2 Fabrizio Carcillo et al.
Unsupervised learning of the brain connectivity dynamic using residual D-net
Seo, Youngjoo, Morante, Manuel, Kopsinis, Yannis, Theodoridis, Sergios
In this paper, we propose a novel unsupervised learning method to learn the brain dynamics using a deep learning architecture named residual D-net. As it is often the case in medical research, in contrast to typical deep learning tasks, the size of the resting-state functional Magnetic Resonance Image (rs-fMRI) datasets for training is limited. Thus, the available data should be very efficiently used to learn the complex patterns underneath the brain connectivity dynamics. To address this issue, we use residual connections to alleviate the training complexity through recurrent multi-scale representation. We conduct two classification tasks to differentiate early and late stage Mild Cognitive Impairment (MCI) from Normal healthy Control (NC) subjects. The experiments verify that our proposed residual D-net indeed learns the brain connectivity dynamics, leading to significantly higher classification accuracy compared to previously published techniques.
Robust and scalable learning of data manifolds with complex topologies via ElPiGraph
Albergante, Luca, Mirkes, Evgeny M., Chen, Huidong, Martin, Alexis, Faure, Louis, Barillot, Emmanuel, Pinello, Luca, Gorban, Alexander N., Zinovyev, Andrei
We present ElPiGraph, a method for approximating data distributions having non-trivial topological features such as the existence of excluded regions or branching structures. Unlike many existing methods, ElPiGraph is not based on the construction of a k-nearest neighbour graph, a procedure that can perform poorly in the case of multidimensional and noisy data. Instead, ElPiGraph constructs elastic principal graphs in a more robust way by minimizing elastic energy, applying graph grammars and explicitly controlling topological complexity. Using trimmed approximation error function makes ElPiGraph extremely robust to the presence of background noise without decreasing computational performance and allows it to deal with complex cases of manifold learning (for example, ElPiGraph can learn disconnected intersecting manifolds). Thanks to the quasi-quadratic nature of the elastic function, ElPiGraph performs almost as fast as a simple k-means clustering and, therefore, is much more scalable than alternative methods, and can work on large datasets containing millions of high dimensional points on a personal computer. The excellent performance of the method opens the possibility to apply resampling and to approximate complex data structures via principal graph ensembles which can be used to construct consensus principal graphs. ElPiGraph is currently implemented in five programming languages and accompanied by a graphical user interface, which makes it a versatile tool to deal with complex data in various fields from molecular biology, where it can be used to infer pseudo-time trajectories from single-cell RNASeq, to astronomy, where it can be used to approximate complex structures in the distribution of galaxies.
Adversarial Training Versus Weight Decay
Galloway, Angus, Tanay, Thomas, Taylor, Graham W.
Performance-critical machine learning models should be robust to input perturbations not seen during training. Adversarial training is a method for improving a model's robustness to some perturbations by including them in the training process, but this tends to exacerbate other vulnerabilities of the model. The adversarial training framework has the effect of translating the data with respect to the cost function, while weight decay has a scaling effect. Although weight decay could be considered a crude regularization technique, it appears superior to adversarial training as it remains stable over a broader range of regimes and reduces all generalization errors. Equipped with these abstractions, we provide key baseline results and methodology for characterizing robustness. The two approaches can be combined to yield one small model that demonstrates good robustness to several white-box attacks associated with different metrics.