This thesis reports the discovery of spectral patterns in ECG signals that exhibit a temporal behavior correlated with an approaching Ventricular Tachyarrhythmic (VTA) event. A computer experiment is performed where a supervised learning algorithm models the ECG signals with the targeted behavior, applies the models on other signals, and analyzes consistencies in the results. The procedure was ...

Network security tests should be periodically conducted to detect vulnerabilities before they are exploited. However, analysis of testing results is resource intensive with many data and requires expertise because it is an unsupervised domain. This paper presents how to automate and improve this analysis through the identification and explanation of device groups with similar vulnerabilities. C...

Feedback from a synthesizer when typing a text has been found useful for children with reading and writing problems. Increased motivation and improvement in spelling skills were observed. A recent project has shown further potentials of this new approach. Children can experiment wi th speech sounds and practice identifying phonemes, discriminating between short and long vowels, rhyming, discove...

Network security tests should be periodically conducted to detect vulnerabilities before they are exploited. However, analysis of testing results is resource intensive with many data and requires expertise because it is an unsupervised domain. This paper presents how to automate and improve this analysis through the identification and explanation of device groups with similar vulnerabilities. C...

Machine learning research, e.g. as described in [Mit97], has had its goal the discovery of relations among observations, i.e. appearances. This is inadequate for science, because there is a reality behind appearance, e.g. material objects are built up from atoms. Atoms are just as real as dogs, only harder to observe, and the atomic theory arose long before there was any idea of how big atoms w...

Interface agents are computer programs that provide personalized assistance to users with their computer-based tasks. Most interface agents achieve personalization by learning a user’s preferences in a given application domain and assisting him according to them. In this work we adopt a different approach to personalization: how to personalize the interaction between interface agents and users ...

Very short computer programs, sometimes consisting of as few as three arithmetic operations in an infinite loop, can generate data that sounds like music when output as raw PCM audio. The space of such programs was recently explored by dozens of individuals within various on-line communities. This paper discusses the programs resulting from this exploratory work and highlights some rather unusu...

It is easy to live for the day. All lazybones do that and legitimately those who have finally taken a rest and enjoy in a relaxed way what is offered to them. The more eventful the better since then it is easy to forget what happened before and since unconnected impressions can be grasped in a particularly fresh way, in a virtually raw way. And in the same way as one might live for the moment, ...

As the name indicates, a renewal process is one that “renews” itself regularly. That is, there is a sequence of times {Tn, n ∈ Z} such that the process after time Tn is independent of what happened before that time and has a distribution that does not depend on n. We have seen examples of such processes before. As a simple example, one could consider a Poisson process with jump times Tn. As ano...

I propose a new measure of common, time-varying tail risk for large cross sections of stock returns. Stock return tails are described by a power law in which the power law exponent is allowed to transition smoothly through time as a function of recent data. It is motivated by asset pricing theory and is estimable via quasi-maximum likelihood. Estimates indicate substantial time variation in sto...