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So you want to be a Data Scientist ?

#artificialintelligence

Microsoft has a mission, "To empower every person and every organization on the planet to achieve more" and they are great words, but action speaks louder than words. You will also hear the phrase'Democratizing AI" being used increasingly over the following months, in other words making Artificial Intelligence available to everyone. I have had the pleasure of working with some of Microsoft's finest over the last two days at a Hackathon in London, covering a number of aspects of Machine Learning, Cognitive Computing and Data Analytics - this post is making some of the learning accessible and available to you. Whether you are just curious or want to start a Data Science journey, this will get you started on your first data science experiment! You need nothing to get started, no previous knowledge, no credit card, just curiosity and a little patience.


Using Digital Fingerprints And Deep Learning To Fight Online Harassment

Forbes - Tech

Activists protest against the gang-rape of a 16-year-old girl in Brazil last year – videos and images of the assault were posted to social media and circulated widely, revictimizing the woman. As Facebook defended itself in a German court against claims that it does too little to counter abusive content on its platform, one of its lawyers made the intriguing claim "There are billions of postings each day. You want us to employ a sort of wonder machine to detect each misuse. Such a machine doesn't exist." For a technology company with a heavy investment in deep learning and filtering technologies that has repeatedly run afoul of free speech advocates for its aggressive stance on content removal this is certainly a curious claim to make.


Efficient fetal-maternal ECG signal separation from two channel maternal abdominal ECG via diffusion-based channel selection

arXiv.org Machine Learning

There is a need for affordable, widely deployable maternal-fetal ECG monitors to improve maternal and fetal health during pregnancy and delivery. Based on the diffusion-based channel selection, here we present the mathematical formalism and clinical validation of an algorithm capable of accurate separation of maternal and fetal ECG from a two channel signal acquired over maternal abdomen.


Understanding machine learning #3: Confusion matrix - not all errors are equal

@machinelearnbot

One of the most typical tasks in machine learning is classification tasks. It may seem that evaluating the effectiveness of such a model is easy. Let's assume that we have a model which, based on historical data, calculates if a client will pay back credit obligations. We evaluate 100 bank customers and our model correctly guesses in 93 instances. That may appear to be a good result – but is it really?


Predicting House Sales

@machinelearnbot

Missingness was an important issue with this dataset. I ignored certain missing items, such as a house not being available on Zillow, under the assumption that they item got dropped for technical reasons in the web scraping process. But others I was less confident about.


High-Dimensional Regularized Discriminant Analysis

arXiv.org Machine Learning

Regularized discriminant analysis (RDA), proposed by Friedman (1989), is a widely popular classifier that lacks interpretability and is impractical for high-dimensional data sets. Here, we present an interpretable and computationally efficient classifier called high-dimensional RDA (HDRDA), designed for the small-sample, high-dimensional setting. For HDRDA, we show that each training observation, regardless of class, contributes to the class covariance matrix, resulting in an interpretable estimator that borrows from the pooled sample covariance matrix. Moreover, we show that HDRDA is equivalent to a classifier in a reduced-feature space with dimension approximately equal to the training sample size. As a result, the matrix operations employed by HDRDA are computationally linear in the number of features, making the classifier well-suited for high-dimensional classification in practice. We demonstrate that HDRDA is often superior to several sparse and regularized classifiers in terms of classification accuracy with three artificial and six real high-dimensional data sets. Also, timing comparisons between our HDRDA implementation in the sparsediscrim R package and the standard RDA formulation in the klaR R package demonstrate that as the number of features increases, the computational runtime of HDRDA is drastically smaller than that of RDA.


Monitoring Plan Optimality Using Landmarks and Domain-Independent Heuristics

AAAI Conferences

When acting, agents may deviate from the optimal plan, either because they are not perfect optimizers or because they interleave multiple unrelated tasks. In this paper, we detect such deviations by analyzing a set of observations and a monitored goal to determine if an observed agent's actions contribute towards achieving the goal. We address this problem without pre-defined static plan libraries, and instead use a planning domain definition to represent the problem and the expected agent behavior. At the core of our approach, we exploit domain-independent heuristics for estimating the goal distance, incorporating the concept of landmarks (actions which all plans must undertake if they are to achieve the goal). We evaluate the resulting approach empirically using several known planning domains, and demonstrate that our approach effectively detects such deviations.


Collective Classification of Social Network Spam

AAAI Conferences

Unsolicited or unwanted messages is a byproduct of virtually every popular social media website. Spammers have become increasingly proficient at bypassing conventional spam filters, prompting a stronger effort to develop new methods that accurately detect spam while simultaneously acting as a more robust classifier against users that modify their behavior in order to avoid detection. This paper shows the usefulness of a relational model that works in conjunction with an independent model. First, an independent model is built using features that characterize individual comments and users, capturing the cases where spam is obvious. Second, a relational model is built, taking advantage of the interconnected nature of users and their comments. By feeding our initial predictions from the independent model into the relational model, we can start to propagate information about spammers and spam comments to jointly infer the labels of all spam comments at the same time. This allows us to capture the obfuscated spam comments missed by the independent model that are only found by looking at the relational structure of the social network. The results from our experiments demonstrates the viability of our method, and shows that models utilizing the underlying structure of the social network are more effective at detecting spam than ones that do not.


ATOL: A Framework for Automated Analysis and Categorization of the Darkweb Ecosystem

AAAI Conferences

We present a framework for automated analysis and categorization of .onion websites in the darkweb to facilitate analyst situational awareness of new content that emerges from this dynamic landscape. Over the last two years, our team has developed a large-scale darkweb crawling infrastructure called OnionCrawler that acquires new onion domains on a daily basis, and crawls and indexes millions of pages from these new and previously known .onion sites. It stores this data into a research repository designed to help better understand Tor’s hidden service ecosystem. The analysis component of our framework is called Automated Tool for Onion Labeling (ATOL), which introduces a two-stage thematic labeling strategy: (1) it learns descriptive and discriminative keywords for different categories, and (2) uses these terms to map onion site content to a set of thematic labels. We also present empirical results of ATOL and our ongoing experimentation with it, as we have gained experience applying it to the entirety of our darkweb repository, now over 70 million indexed pages. We find that ATOL can perform site-level thematic label assignment more accurately than keywordbased schemes developed by domain experts — we expand the analyst-provided keywords using an automatic keyword discovery algorithm, and get 12% gain in accuracy by using a machine learning classification model. We also show how ATOL can discover categories on previously unlabeled onions and discuss applications of ATOL in supporting various analyses and investigations of the darkweb.


Preventive Leak Detection for High Pressure Gas Transmission Networks

AAAI Conferences

Recent developments in SCADA (Supervisory Control and Data Acquisition) systems for physical infrastructure, such as high pressure gas pipeline systems and electric grids, have generated enormous amounts of time series data. This data brings great opportunities for advanced knowledge discovery and data mining methods to identify system failures faster and earlier than operation experts. This paper presents our effort in collaboration with a utility company to solve a grand challenge; namely, to use advanced data mining methods to detect leaks on a high pressure gas transmission system. Leak detection models with unsupervised learning tasks were developed analyzing billions of data records to identify leaks of different sizes and impacts, with very low false positive rates. In particular, our solution was able to identify small leaks leading to rupture events. The model also identified small leaks not identifiable with current detection systems. Such high-fidelity early identification enables operation personnel to take preventive measures against possible catastrophic events. We then formulate several generic detection methods with models derived from time series anomaly detection methods. We show that our leak detection models are superior to the SCADA alarm system, a mass balance model and other generic time series anomaly detection models in terms of both detection accuracy and computation time.