Efficient and accurate identification of network anomalies is significant to network security systems. It is highly challenging to detect abnormal behaviors in the increasing network data accurately. Currently, classification methods based on feature extraction of autoencoders have been proven to be suitable for network anomaly detection. However, traditional detection models with autoencoders have unsatisfying detection accuracy in the face of massive network features. In addition, the hyperparameter optimization of their models cannot be effectively solved. In this work, based on the improvement of variational autoencoders, stacked sparse shrink variational autoencoders (S3VAEs) are designed. In addition, anUnbalancedXGBoost classifier based onGenetic simulated annealing particle swarm optimization (UXG) is proposed. Finally, the feature extractor of S3VAEs is combined with the UXG classifier, and the anomaly detection model is obtained. Experimental results based on four real-life data sets demonstrate that the proposed anomaly detection model achieves higher classification accuracy and F1 than several state-of-the-art algorithms.

With the rapid development of the Internet, various network invasive behaviors are increasing rapidly. This seriously threatens the economic development of individuals, enterprises, and society. Network intrusion detection is important in network security systems, which can be regarded as a classification problem. It aims to distinguish between the specific categories of various network behaviors and determine whether the behavior belongs to network intrusion. However, network intrusions present a diverse and fast-changing trend, making categorizing difficult. Due to feature redundancy, uneven distribution of sample numbers, and inefficient parameter optimization, traditional rule-based approaches fail to achieve satisfying classification accuracy. This work proposes a multi-classification intrusion detection model based on Stacked Sparse Shrink AutoEncoder (SSSAE), Genetic Simulated annealing-based particle swarm optimization optimized Tabnet classifier (GS-Tabnet), and Decision Fusion (DF), called for SGTD short. Among them, SSSAE extracts multiple feature sets from the input data. Then GS-Tabnet trains a classifier for each feature set. Finally, the decision fusion fuses the results from these classifiers to obtain the final classification result. SGTD is compared with eight multi-classification benchmark models, and its intrusion detection accuracy is superior to its peers.

Efficient and accurate identification of network anomalies is of great significance to the construction of network security systems in the information age. It is highly challenging to accurately detect abnormal behaviors in the increasing network data. Currently, classification methods based on feature extraction of autoencoders have been proven to be suitable for network anomaly detection. However, traditional detection models with autoencoders have poor detection accuracy in the face of massive network features. In addition, the hyperparameter optimization of their models cannot be effectively solved. For network anomaly detection, this work proposes a new network anomaly detection method named SAXP, which integrates Stacked sparse shrink Autoencoders and a XGBoost model based on genetic simulated annealing Particle swarm optimization (GSPSO). Specifically, features extracted by stacked sparse shrink autoencoders are introduced into the XG Boost model for classification, and GSPSO is used to optimize the hyperparameters of XGBoost. Experimental results based on two real-life data sets demonstrate that the proposed SAXP achieves higher recognition accuracy than several state-of-the-art algorithms.

Accurately identifying network intrusion cannot only help individuals and enterprises better deal with network security problems, but also maintain the Internet environment. Currently, classification methods with autoencoders for feature learning have been proved to be suitable for the network intrusion detection. This work proposes a new hybrid classification method named SABD for network intrusion detection. SABD integrates Stacked sparse contractive autoencoders, Attention-based Bidirectional long-term and short-term memory (LSTM), and Decision fusion. SABD integrates the feature extraction of stacked sparse contractive autoencoders with the classification ability of attention-based bidirectional LSTM. Specifically, stacked sparse contractive autoencoders are used for extracting features, which are sent to the attention-based bidirectional LSTM for the classification. Finally, the decision fusion algorithm is adopted to integrate classification results of multiple classifiers and yield the final results. Experimental results based on real-life UNSW-NB15 data demonstrate that the proposed SABD outperforms its state-of-the-art peers in terms of classification accuracy.

Water quality prediction refers to the prediction of future water quality changes based on past data. Traditional prediction models cannot capture intricate and nonlinear features. Typical machine learning methods extract nonlinear characteristics, but they suffer from overfitting problems due to data noise. Most current deep learning models have problems of gradient disappearance and explosion, and often fail to capture long-term dependence. To solve above-mentioned problems, this work proposes a multi-indicator time series prediction method named SG-Informer for river water quality prediction. SG-Informer integrates the Savitsky-Golay filter, the ProbSparse self-attention mechanism of an encoder, and a generative style decoder, serving as data smoothing and noise elimination, network scale reduction, and prediction speed improvement, respectively. SG-Informer establishes a high-quality water quality time prediction model, which effectively predicts the future water quality time series trend. Based on real-life data sets of water quality, multi-indicator and single-indicator prediction experiments are performed. Experimental results demonstrate that the proposed SG-Informer outperforms several state-of-the-art prediction methods in terms of prediction accuracy.

Prediction of pollution is an increasingly important problem. It can impact individuals and their health, e.g. asthma patients can be greatly affected by air pollution. Traditional air pollution prediction methods have limitations. Machine learning provides one approach that can offer new opportunities for prediction of air pollution. There are however many different machine learning approaches and identifying the best one for the problem at hand is often challenging. In this paper air pollution data, specifically particulate matter of less than 2.5 micrometers (PM2.5) was collected from a variety of web-based resources and following, data cleansing analysed with different machine learning models including linear regression, Artificial Neural Networks and Long Short Term Memory recurrent neural networks. We consider the accuracy and the ability of these different models to predict unhealthy levels of pollution. The advantages and disadvantages of these models are also discussed.