78 research outputs found
A Grid-aware Intrusion Detection System
www.imm.dtu.dk Existing Intrusion Detection Systems (IDS) are not designed to deal with any specific types of systems. The purpose of this work is to investigate the possibility of Grid-focused IDS. The main stress is put on feature selection and performance of the system. An existing framework, IDSNet, is used as a basis for considerations and development. An algorithm based on Self-Organizing Map has been selected for pattern discovery in traffic analysis. No Grid environment was available for testing, therefore no real-life experiments could have been performed, and main focus was shifted to system performance and away from feature selection. It is shown that the performance of the system greatly depends on the efficiency of the underlying framework. A number of optimizations are shown that improve the algorithm’s performance by 2 orders of magnitude. i
Summary
In the following, I will use technical terms without explanation as it gives the freedom to describe the project in a shorter form for those who already know. The thesis is about condition monitoring of large diesel engines from acoustic emission signals. The experiments have been focused on a specific and severe fault called scuffing. The fault is generally assumed to arise from increased interaction between the piston and liner. For generating experimental data destructive tests with no lubrication, oil has been carried out. Focus has been on modeling the normal condition and detecting the increased interaction due to the lack of lubrication as a deviation from the normal. Linear instantaneous blind source separation is capable of picking out the relevant hidden signals. Those hidden signals and the estimated noise level can be used to model the normal-condition, and faults can be detected as outliers in that model. Among the investigated methods the Mean field independent component analysis with diagonal noise covariance matrix models is best at modeling the observed signals. Nevertheless, this does not imply that this is th
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