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One-class Collective Anomaly Detection based on Long Short-Term Memory Recurrent Neural Networks

arXiv.org Machine Learning

Intrusion detection for computer network systems has been becoming one of the most critical tasks for network administrators today. It has an important role for organizations, governments and our society due to the valuable resources hosted on computer networks. Traditional misuse detection strategies are unable to detect new and unknown intrusion types. In contrast, anomaly detection in network security aims to distinguish between illegal or malicious events and normal behavior of network systems. Anomaly detection can be considered as a classification problem where it builds models of normal network behavior, of which it uses to detect new patterns that significantly deviate from the model. Most of the current approaches on anomaly detection is based on the learning of normal behavior and anomalous actions. They do not include memory that is they do not take into account previous events classify new ones. In this paper, we propose a one class collective anomaly detection model based on neural network learning. Normally a Long Short Term Memory Recurrent Neural Network (LSTM RNN) is trained only on normal data, and it is capable of predicting several time steps ahead of an input. In our approach, a LSTM RNN is trained on normal time series data before performing a prediction for each time step. Instead of considering each time-step separately, the observation of prediction errors from a certain number of time-steps is now proposed as a new idea for detecting collective anomalies. The prediction errors of a certain number of the latest time-steps above a threshold will indicate a collective anomaly. The model is evaluated on a time series version of the KDD 1999 dataset. The experiments demonstrate that the proposed model is capable to detect collective anomaly efficiently


An Encoder-Decoder Based Approach for Anomaly Detection with Application in Additive Manufacturing

arXiv.org Machine Learning

We present a novel unsupervised deep learning approach that utilizes the encoder-decoder architecture for detecting anomalies in sequential sensor data collected during industrial manufacturing. Our approach is designed not only to detect whether there exists an anomaly at a given time step, but also to predict what will happen next in the (sequential) process. We demonstrate our approach on a dataset collected from a real-world testbed. The dataset contains images collected under both normal conditions and synthetic anomalies. We show that the encoder-decoder model is able to identify the injected anomalies in a modern manufacturing process in an unsupervised fashion. In addition, it also gives hints about the temperature non-uniformity of the testbed during manufacturing, which is what we are not aware of before doing the experiment.


Fraud Detection Using Random Forest, Neural Autoencoder, and Isolation Forest Techniques

#artificialintelligence

With global credit card fraud loss on the rise, it is important for banks, as well as e-commerce companies, to be able to detect fraudulent transactions (before they are completed). According to the Nilson Report, a publication covering the card and mobile payment industry, global card fraud losses amounted to $22.8 billion in 2016, an increase of 4.4% over 2015. This confirms the importance of the early detection of fraud in credit card transactions. Fraud detection in credit card transactions is a very wide and complex field. Over the years, a number of techniques have been proposed, mostly stemming from the anomaly detection branch of data science. In the first scenario, we can deal with the problem of fraud detection by using classic machine learning or statistics-based techniques. We can train a machine learning model or calculate some probabilities for the two classes (legitimate transactions and fraudulent transactions) and apply the model to new transactions so as to estimate their legitimacy.


TensorFlow 2 Tutorial: Get Started in Deep Learning With tf.keras

#artificialintelligence

You can easily create learning curves for your deep learning models. First, you must update your call to the fit function to include reference to a validation dataset. This is a portion of the training set not used to fit the model, and is instead used to evaluate the performance of the model during training.


Anomaly Detection Using Isolation Forest in Python Paperspace Blog

#artificialintelligence

From bank fraud to preventative machine maintenance, anomaly detection is an incredibly useful and common application of machine learning. The isolation forest algorithm is a simple yet powerful choice to accomplish this task. You can run the code for this tutorial for free on the ML Showcase. An outlier is nothing but a data point that differs significantly from other data points in the given dataset. Anomaly detection is the process of finding the outliers in the data, i.e. points that are significantly different from the majority of the other data points.