БАГАТОШАРОВА МОДЕЛЬ ТА МЕТОД НАВЧАННЯ ДЛЯ ДЕТЕКТУВАННЯ ШКІДЛИВОГО ТРАФІКУ НА ОСНОВІ АНСАМБЛЮ ДЕРЕВ РІШЕНЬ

The model and training method of multilayer feature extractor and decision rules for a malware traffic detector is proposed. The feature extractor model is based on a convolutional sparse coding network whose sparse encoder is approximated by a regression random forest model according to the principles of knowledge distillation. In this case, an algorithm of growing sparse coding neural gas has been developed for unsupervised training the features extractor with automatic determination of the required number of features on each layer. As for feature extractor, at the training phase to implement of sparse coding the greedy L1-regularized method of Orthogonal Matching Pursuit was used, and at the knowledge distillation phase, the L1-regularized method at the least angles (Least regression algorithm) was additionally used. Due to the explaining-away effect, the extracted features are uncorrelated and robust to noise and adversarial attacks. The proposed feature extractor is unsupervised trained to separate the explanatory factors and allows to use the unlabeled training data, which are usually quite large, with the maximum efficiency. As a model of the decision rules proposed to use the binary encoder of input observations based on an ensemble of decision trees and information-extreme closed hyper-surfaces (containers) for class separation, that are recovery in radial-basis of Hemming' binary space. The addition of coding trees is based on the boosting principle, and the radius of class containers is optimized by direct search. The information-extreme classifier is characterized by low computational complexity and high generalization capacity for small sets of labeled training data. The verification results of the trained model on open CTU test data sets confirm the suitability of the proposed algorithms for practical application since the accuracy of malware traffic detection is 96.1 %.

Optimization of Traffic Detector Layout Based on Complex Network Theory

With the recent development of traffic networks, traffic detector layout has become very complicated, due to the complexity of traffic network structures and states. Thus, this paper presents an optimal method for traffic detector layout based on network centrality using complex network theory. It mainly depends on the topology of the traffic network, and does not depend on pre-conditions (e.g., OD (Origin Destination)) traffic, path traffic, prior matrix, and so on) or consider route-choosing behavior too much. Considering the travel time, OD demand, observation demand of urban managers, dynamic characteristic of the traffic network, detector failure, and so on, an optimization model for traffic detector layout is established, which is called the Traffic Network Centrality Model (TNCM). Numerical experiments are conducted, based on data from the Sioux Falls network, which demonstrate that the model has a strong practical value. TNCM is not only helpful in reducing the traffic detector layout cost, but also improves the monitoring revenue of the traffic network in complex scenarios, which offers a promising way of thinking about the optimization of traffic detector layout schemes.

Fault Data Detection of Traffic Detector Based on Wavelet Packet in the Residual Subspace Associated with PCA

To improve the accuracy and efficiency of fault data identification of traffic detectors is crucial in order to decrease the probability of unexpected failures of the intelligent transportation system (ITS). Since convolutional fault data recognition based on traffic flow three-parameter law has a poor capability for multiscale of fault data, PCA (principal component analysis) is adopted for traffic fault data identification. This paper proposes the fault data detection models based on the PCA model, MSPCA (multiscale principal component analysis) model and improved MSPCA model, respectively. In order to improve the recognition rate of traffic detectors’ fault data, the improved MSPCA model combines the wavelet packet energy analysis and PCA to achieve traffic detector data fault identification. On the basis of traditional MSPCA, wavelet packet multi-scale decomposition is used to get detailed information, and principal component analysis models are established on different scale matrices, and fault data are separated by wavelet packet energy difference. Through case analysis, the feasibility verification of traffic flow data identification method is carried out. The results show that the improved method proposed in this paper is effective for identifying traffic fault data.

Real-Time Simulation of Dynamic Traffic Flow with Traffic Data Assimilation Approach

The real-time traffic state estimation we propose uses a state-space model considering the variability of the fundamental diagram (FD) and sensing data. Serious congestion was caused by vehicle evacuation in many Sanriku coast cities following the great East Japan earthquake on March 11, 2011. Many of the vehicles in these congested queues were caught in the enormous tsunami after the earthquake [1]. Safe, efficient evacuation and rescue and restoration require that dynamic traffic states be monitored in real time especially in natural disasters. Variational theory (VT) based on kinematic wave theory is used for the system model, with probe vehicle and traffic detector data used to for measurement data. Our proposal agrees better with simulated benchmark traffic states than deterministic VT results do.