Performance Analysis
WrestleMania 33 Matches: Roman Reigns Expected To Beat The Undertaker At 2017 WWE PPV
Roman Reigns got his payback on The Undertaker on the most recent edition of "Monday Night Raw." The three-time WWE Champion ended the show by delivering a Spear to the Deadman, and he's now expected to win their WrestleMania 33 match. The Undertaker made a surprise return to WWE, appearing in the middle of the ring during Reigns' match with Braun Strowman. The Deadman delivered a Chokeslam to Strowman, allowing Reigns to attack The Undertaker when his back was turned. Two weeks earlier, The Undertaker hit Reigns with a ChokeSlam and the WrestleMania match was made.
On the Use of Default Parameter Settings in the Empirical Evaluation of Classification Algorithms
Bagnall, Anthony, Cawley, Gavin C.
We demonstrate that, for a range of state-of-the-art machine learning algorithms, the differences in generalisation performance obtained using default parameter settings and using parameters tuned via cross-validation can be similar in magnitude to the differences in performance observed between state-of-the-art and uncompetitive learning systems. This means that fair and rigorous evaluation of new learning algorithms requires performance comparison against benchmark methods with best-practice model selection procedures, rather than using default parameter settings. We investigate the sensitivity of three key machine learning algorithms (support vector machine, random forest and rotation forest) to their default parameter settings, and provide guidance on determining sensible default parameter values for implementations of these algorithms. We also conduct an experimental comparison of these three algorithms on 121 classification problems and find that, perhaps surprisingly, rotation forest is significantly more accurate on average than both random forest and a support vector machine.
Day22: Splitting data, calculating metrics, cross-validations
Today I want to showcase "better" and more tidy ways of using Python. The Jupyter Notebook for this little project is found here. Originally, I would slice the data by the index. The problem is that the slicing is not random. Scikit-learn has a function train_test_split() to randomly split the data into test and training sets.
Gennady Golovkin vs. Daniel Jacobs: LIVE Round By Round Scorecard, Actual Start Time For HBO PPV Boxing Event
Preview: Gennady "GGG" Golovkin (36-0, 33 KOs) faces challenger Daniel Jacobs (32-1, 29 KOs) in a middleweight unification bout Saturday night at Madison Square Garden in New York. Coverage of the fight will be on HBO pay-per-view. On the line are the WBA (Super), WBC, and IBO middleweight titles with two boxers entering the fight on knockout streaks. Golovkin, a native of Kazakhstan, has knocked out 23 opponents in a row. Jacobs, a native of Brooklyn, has 12 knockout victories in a row.
Blockchains for Artificial Intelligence
And, it was first published on Dataconomy on Dec 21, 2016; I'm reposting here for ease of access.] In recent years, AI (artificial intelligence) researchers have finally cracked problems that they've worked on for decades, from Go to human-level speech recognition. A key piece was the ability to gather and learn on mountains of data, which pulled error rates past the success line. In short, big data has transformed AI, to an almost unreasonable level. Blockchain technology could transform AI too, in its own particular ways. Some applications of blockchains to AI are mundane, like audit trails on AI models. Some appear almost unreasonable, like AI that can own itself -- AI DAOs. All of them are opportunities. This article will explore these applications. Before we discuss applications, let's first review what's different about blockchains compared to traditional big-data distributed databases like MongoDB. We can think of blockchains as "blue ocean" databases: they escape the "bloody red ocean" of sharks competing in an existing market, opting instead to be in a blue ocean of uncontested market space.
Aggregation of Classifiers: A Justifiable Information Granularity Approach
Nguyen, Tien Thanh, Pham, Xuan Cuong, Liew, Alan Wee-Chung, Pedrycz, Witold
In this study, we introduce a new approach to combine multi-classifiers in an ensemble system. Instead of using numeric membership values encountered in fixed combining rules, we construct interval membership values associated with each class prediction at the level of meta-data of observation by using concepts of information granules. In the proposed method, uncertainty (diversity) of findings produced by the base classifiers is quantified by interval-based information granules. The discriminative decision model is generated by considering both the bounds and the length of the obtained intervals. We select ten and then fifteen learning algorithms to build a heterogeneous ensemble system and then conducted the experiment on a number of UCI datasets. The experimental results demonstrate that the proposed approach performs better than the benchmark algorithms including six fixed combining methods, one trainable combining method, AdaBoost, Bagging, and Random Subspace.
Classification in biological networks with hypergraphlet kernels
Lugo-Martinez, Jose, Radivojac, Predrag
Biological and cellular systems are often modeled as graphs in which vertices represent objects of interest (genes, proteins, drugs) and edges represent relational ties among these objects (binds-to, interacts-with, regulates). This approach has been highly successful owing to the theory, methodology and software that support analysis and learning on graphs. Graphs, however, often suffer from information loss when modeling physical systems due to their inability to accurately represent multiobject relationships. Hypergraphs, a generalization of graphs, provide a framework to mitigate information loss and unify disparate graph-based methodologies. In this paper, we present a hypergraph-based approach for modeling physical systems and formulate vertex classification, edge classification and link prediction problems on (hyper)graphs as instances of vertex classification on (extended, dual) hypergraphs in a semi-supervised setting. We introduce a novel kernel method on vertex- and edge-labeled (colored) hypergraphs for analysis and learning. The method is based on exact and inexact (via hypergraph edit distances) enumeration of small simple hypergraphs, referred to as hypergraphlets, rooted at a vertex of interest. We extensively evaluate this method and show its potential use in a positive-unlabeled setting to estimate the number of missing and false positive links in protein-protein interaction networks.
On the benefits of output sparsity for multi-label classification
Chzhen, Evgenii, Denis, Christophe, Hebiri, Mohamed, Salmon, Joseph
The multi-label classification framework, where each observation can be associated with a set of labels, has generated a tremendous amount of attention over recent years. The modern multi-label problems are typically large-scale in terms of number of observations, features and labels, and the amount of labels can even be comparable with the amount of observations. In this context, different remedies have been proposed to overcome the curse of dimensionality. In this work, we aim at exploiting the output sparsity by introducing a new loss, called the sparse weighted Hamming loss. This proposed loss can be seen as a weighted version of classical ones, where active and inactive labels are weighted separately. Leveraging the influence of sparsity in the loss function, we provide improved generalization bounds for the empirical risk minimizer, a suitable property for large-scale problems. For this new loss, we derive rates of convergence linear in the underlying output-sparsity rather than linear in the number of labels. In practice, minimizing the associated risk can be performed efficiently by using convex surrogates and modern convex optimization algorithms. We provide experiments on various real-world datasets demonstrating the pertinence of our approach when compared to non-weighted techniques.
Discriminate-and-Rectify Encoders: Learning from Image Transformation Sets
Tacchetti, Andrea, Voinea, Stephen, Evangelopoulos, Georgios
The complexity of a learning task is increased by transformations in the input space that preserve class identity. Visual object recognition for example is affected by changes in viewpoint, scale, illumination or planar transformations. While drastically altering the visual appearance, these changes are orthogonal to recognition and should not be reflected in the representation or feature encoding used for learning. We introduce a framework for weakly supervised learning of image embeddings that are robust to transformations and selective to the class distribution, using sets of transforming examples (orbit sets), deep parametrizations and a novel orbit-based loss. The proposed loss combines a discriminative, contrastive part for orbits with a reconstruction error that learns to rectify orbit transformations. The learned embeddings are evaluated in distance metric-based tasks, such as one-shot classification under geometric transformations, as well as face verification and retrieval under more realistic visual variability. Our results suggest that orbit sets, suitably computed or observed, can be used for efficient, weakly-supervised learning of semantically relevant image embeddings.
Propensity score prediction for electronic healthcare databases using Super Learner and High-dimensional Propensity Score Methods
Ju, Cheng, Combs, Mary, Lendle, Samuel D, Franklin, Jessica M, Wyss, Richard, Schneeweiss, Sebastian, van der Laan, Mark J.
The optimal learner for prediction modeling varies depending on the underlying data-generating distribution. Super Learner (SL) is a generic ensemble learning algorithm that uses cross-validation to select among a "library" of candidate prediction models. The SL is not restricted to a single prediction model, but uses the strengths of a variety of learning algorithms to adapt to different databases. While the SL has been shown to perform well in a number of settings, it has not been thoroughly evaluated in large electronic healthcare databases that are common in pharmacoepidemiology and comparative effectiveness research. In this study, we applied and evaluated the performance of the SL in its ability to predict treatment assignment using three electronic healthcare databases. We considered a library of algorithms that consisted of both nonparametric and parametric models. We also considered a novel strategy for prediction modeling that combines the SL with the high-dimensional propensity score (hdPS) variable selection algorithm. Predictive performance was assessed using three metrics: the negative log-likelihood, area under the curve (AUC), and time complexity. Results showed that the best individual algorithm, in terms of predictive performance, varied across datasets. The SL was able to adapt to the given dataset and optimize predictive performance relative to any individual learner. Combining the SL with the hdPS was the most consistent prediction method and may be promising for PS estimation and prediction modeling in electronic healthcare databases.