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Devil. ATM Data:. The. in. Size , stationarity ,. δαίμωνες. and other. Massimiliano Zanin. 螃蟹挖洞根據他們的砲彈的大小. Crabs dig holes according to the size of their shells. Richard Ernest Bellman. Curse of dimensionality.
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Devil ATM Data: The in Size, stationarity, δαίμωνες and other Massimiliano Zanin
螃蟹挖洞根據他們的砲彈的大小 Crabs dig holes according to the size of their shells
Richard Ernest Bellman Curse of dimensionality Given the large search space, for every desired significance an hypothesis can be found A. Zimek, E. Schubert, and H. P. Kriegel (2012)
Richard Ernest Bellman Curse of dimensionality
Richard Ernest Bellman Curse of dimensionality
Richard Ernest Bellman Curse of dimensionality J. Cohen, 1962 All papers in a volume of Journal of Abnormal and Social Psychology .18 for small effects .48 for medium effects .83 for large effects Average power: Half of the results are not significant!
John P. A. Ioannidis Why Most Published Research Findings Are False Main reasons behind false results: Small studies (small sample size) High number of relationships Financial and other interests Hot scientific fields
What about ATM? Two main problems: High feature space dimension Low number of instances
What about ATM? Two main problems: High feature space dimension Low number of instances Feature selection techniques
What about ATM? Two main problems: High feature space dimension Low number of instances Analyze events leading to these instances Get more data!
Divide et impera Divide and rule
Feature 2 Feature 1 Simpson’s Paradox Two groups of events Each one associated with a positive correlation between f1 and f2
Feature 2 Feature 1 Simpson’s Paradox Two groups of events Each one associated with a positive correlation between f1 and f2 A spurious negative correlation appears when considering both groups
C. R. Charig et al. Comparison of treatment of renal calculi by open surgery, percutaneous nephrolithotomy, and extracorporeal shockwave lithotripsy 2 treatments: A - strong surgical intervention B - percutaneous nephrolithotomy 2 groups: Small stones Large stones
C. R. Charig et al. Comparison of treatment of renal calculi by open surgery, percutaneous nephrolithotomy, and extracorporeal shockwave lithotripsy
C. R. Charig et al. Comparison of treatment of renal calculi by open surgery, percutaneous nephrolithotomy, and extracorporeal shockwave lithotripsy
οὐ λέγουσι τὸ διὰ τί περὶ οὐδενός ... these do not tell us why a thing is so
W. M. Briggs Global Warming Increases Disastrous Music: A Scientific Paper
W. M. Briggs Global Warming Increases Disastrous Music: A Scientific Paper Raising temperature might be boiling brains. Global warming will drive the population mad through an intense barrage of awful, atonal, crude, childishly limited and harmful popular music.
Our safety research Input data Target Daily average delays Number of safety events p-value < 0.01 Classification score > 61%
Our safety research Input data Target Daily operations (in the previous day) Number of safety events p-value < 0.001 Classification score > 83%
Πάντα ῥεῖ καὶ οὐδὲν μένει Everything flows, nothing stands still
Stationarity The properties of a system do not depend explicitly on time Mean and variance do not change over time or position
Stationarity The properties of a system do not depend explicitly on time Mean and variance do not change over time or position
Stationarity The properties of a system do not depend explicitly on time Mean and variance do not change over time or position
Rara avis in terris nigroque simillima cygno A rare bird in the lands, very much like a black swan
Black swan An event that was unprecedented and unexpected at the point in time it occurred. However, after evaluating the surrounding context, domain experts can usually conclude: “it was bound to happen” The Black Swan, N. N. Taleb, 2007
Black swan Problem: Inside vs. Outside (a probability distribution)
Black swan Inside vs. Outside Unpredictable vs. Predictable Same mechanisms vs. New processes Black swan vs. Dragon-King
Black swan Mid air collision <> Loss of separation Eyjafjallajökull (2010) <> Day with extreme delays Runway incursion <> Wrong communication Event aggregation can be dangerous!
In resume: Sample size Grouping Causality Stationarity Extreme events
In resume: Know your data mz@innaxis.org