Knowledge mining sensory evaluation data: genetic programming, statistical techniques, and swarm optimization

Knowledge mining sensory evaluation data is a challenging process due to extreme sparsity of the data, and a large variation in responses from different members (called assessors) of the panel. The main goals of knowledge mining in sensory sciences are understanding the dependency of the perceived liking score on the concentration levels of flavors’ ingredients, identifying ingredients that drive liking, segmenting the panel into groups with similar liking preferences and optimizing flavors to maximize liking per group. Our approach employs (1) Genetic programming (symbolic regression) and ensemble methods to generate multiple diverse explanations of assessor liking preferences with confidence information; (2) statistical techniques to extrapolate using the produced ensembles to unobserved regions of the flavor space, and segment the assessors into groups which either have the same propensity to like flavors, or are driven by the same ingredients; and (3) two-objective swarm optimization to identify flavors which are well and consistently liked by a selected segment of assessors

Making the End-User a Priority in Benchmarking: OrionBench for Unsupervised Time Series Anomaly Detection

Time series anomaly detection is a prevalent problem in many application domains such as patient monitoring in healthcare, forecasting in finance, or predictive maintenance in energy. This has led to the emergence of a plethora of anomaly detection methods, including more recently, deep learning based methods. Although several benchmarks have been proposed to compare newly developed models, they usually rely on one-time execution over a limited set of datasets and the comparison is restricted to a few models. We propose OrionBench -- a user centric continuously maintained benchmark for unsupervised time series anomaly detection. The framework provides universal abstractions to represent models, extensibility to add new pipelines and datasets, hyperparameter standardization, pipeline verification, and frequent releases with published benchmarks. We demonstrate the usage of OrionBench, and the progression of pipelines across 15 releases published over the course of three years. Moreover, we walk through two real scenarios we experienced with OrionBench that highlight the importance of continuous benchmarks in unsupervised time series anomaly detection

Transfer Learning for Predictive Models in Massive Open Online Courses

Abstract. Data recorded while learners are interacting with Massive Open Online Courses (MOOC) platforms provide a unique opportunity to build predictive models that can help anticipate future behaviors and develop interventions. But since most of the useful predictive problems are defined for a real-time framework, using knowledge drawn from previous courses becomes crucial. To address this challenge, we designed a set of processes that take advantage of knowledge from both previous courses and previous weeks of the same course to make real time predictions on learners behavior. In particular, we evaluate multiple transfer learning methods. In this article, we present our results for the stopout prediction problem (predicting which learners are likely to stop engaging in the course). We believe this paper is a first step towards addressing the need of transferring knowledge across courses