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Science and Technology links (July 20th 2019)
- Researchers solve the Rubik’s cube puzzle using machine learning (deep learning).
- There has been a rise in the popularity of “deep learning” following some major breakthroughs in tasks like image recognition. Yet, at least as far as recommender systems are concerned, there are reasons to be skeptical of the good results being reported:
In this work, we report the results of a systematic analysis of algorithmic proposals for top-n recommendation tasks. Specifically, we considered 18 algorithms that were presented at top-level research conferences in the last years. Only 7 of them could be reproduced with reasonable effort. For these methods, it however turned out that 6 of them can often be outperformed with comparably simple heuristic methods, e.g., based on nearest-neighbor or graph-based techniques. The remaining one clearly outperformed the baselines but did not consistently outperform a well-tuned non-neural linear ranking method. Overall, our work sheds light on a number of potential problems in today’s machine learning scholarship and calls for improved scientific practices in this area.
- Your blood contains about four grams of glucose/sugar (it is a tiny amount).
- Our brain oscillates at a rate of about 40 Hz (40 times per second). Some researchers may have found the cells responsible for coordinating these waves.
- Are we suffering from record-setting heat waves? A recent American government report concludes that we are not:
(…) the warmest daily temperature of the year increased in some parts of the West over the past century, but there were decreases in almost all locations east of the Rocky Mountains. In fact, all eastern regions experienced a net decrease (…), most notably the Midwest (about 2.2°F) and the Southeast (roughly 1.5°F). (…) As with warm daily temperatures, heat wave magnitude reached a maximum in the 1930s.
The same report observes that cold extremes have become less common, however.