Insights from IEEE Big Data 16

I have attended the IEEE Big Data 16 conference in Washington DC. I thank my company for sponsoring the trip. The conference included a special symposium dedicated to manufacturing. The symposium hosted some participants of the Bosch Production Line Performance competition from Kaggle.

I'll list here a few notes I took during the conference.

  • Streaming Processing. I heard about the most popular architectures nowadays, and I highly recommend reading the blog posts by the authors of such architectures:
  • K-Spectral Centroid. The K-Spectral Centroid algorithm clusters time series by their shape, and finds the most representative shape (the cluster centroid) for each cluster.
  • K-D Tree partition: an algorithm for space partitioning.
  • Database Decay. Interesting keynote by Michael Stonebraker. Shortly, large applications often share a centralized database used by different groups of a company. The DBA point of view:
    • High Risk. When changing a DB schema, I need to find applications all around in the company and update them accordingly (do I have budget for that?).
    • Low Risk. No change in schema, I do a workaround in data.
    • Claim. DBA want to lower the risk. --> no change in schema --> ER diagram diverges from reality --> database decay.
    • At some point, a total rewrite is the only way forward.
    • If you work in analytics getting data from operational DB, you realize data is getting more and more dirty.
  • PMML Scoring Engine. Max Ferguson introduced what a Predictive Model Markup Language (PMML) is. Basically, if you train a model and want to share it in a different application, PMML is a standard that defines how models should be stored as an XML.
  • Uncertainty in RFs. Random Forests can express uncertainty. One just needs to look at distribution of predictions among the decision trees of the model.
  • Bosch. Rumi Ghosh introduced the data science team at Bosch.
    • Insight from production plants: plant managers prefer interpretable models (logistic regression or decision tree) over black box models.
    • Research directions:
    • Root cause analysis (via Bayesian inference)
    • Class imbalance
  • 3 Approaches in Kaggle Competition. Bohdan Pavlyshenko gave a talk on the three approaches he explored during the Kaggle competition about failure detection:
    • Pure machine learning approach. 2-Levels of model ensembling, a pure black-box.
    • Generalized Linear Model with Lasso regularization. Informative about feature impact.
    • Bayesian model in BUGS. It enables to obtain the estimate of the probability distribution for each coefficient.
  • FTLR. Follow the regularized leader: a feature engineering method used to convert all categorical feature into one numerical feature.
  • CRF. Conditional Random Fields is a class of predictive models used when the dataset is represented as a graph. Each node is a sample with a vector X and a target variable y.