Radar Working State Recognition Based on the Unsupervised and Incremental Method

Radar working state recognition is the basis of cognitive electronic countermeasures. Aiming at the problem that the traditional supervised recognition technology is difficult to obtain prior information and process the incremental signal data stream, an unsupervised and incremental recognition method is proposed. This method is based on a backpropagation (BP) neural network to construct a recognition model. Firstly, the particle swarm optimization (PSO) algorithm is used to optimize the preference parameter and damping factor of affinity propagation (AP) clustering. Then, the PSO-AP algorithm is used to cluster unlabeled samples to obtain the best initial clustering results. The clustering results are input as training samples into the BP neural network to train the recognition model, which realizes the unsupervised recognition. Secondly, the incremental AP (IAP) algorithm based on the K -nearest neighbor (KNN) idea is used to divide the incremental samples by calculating the closeness between samples. The incremental samples are added to the BP recognition model as a new known state to complete the model update, which realizes incremental recognition. The simulation experiments on three types of radar data sets show that the recognition accuracy of the proposed model can reach more than 83%, which verifies the feasibility and effectiveness of the method. In addition, compared with the AP algorithm and K -means algorithm, the improved AP method improves 59.4%, 17.6%, and 53.5% in purity, rand index (RI), and F -measure indexes, respectively, and the running time is at least 34.8% shorter than the AP algorithm. The time of processing incremental data is greatly reduced, and the clustering efficiency is improved. Experimental results show that this method can quickly and accurately identify radar working state and play an important role in giving full play to the adaptability and timeliness of the cognitive electronic countermeasures.

Towards Sustainable Urbanization. Learning from What’s Out There

The incremental recognition of the importance of land as a finite resource has led to the adoption and implementation of an increasing number of sustainable land use practices in European cities and regions. This paper reflects on these experiences, building on the evidence collected in the framework of the ESPON SUPER pan-European research project. In particular, the authors look at the project’s database, which includes 235 examples of sustainable urbanization interventions gathered from all around Europe. In doing so, they reflect on the outcomes of these interventions, focusing on both their scope and objectives and the types of instruments that were adopted in their implementation. The objective of this contribution is to critically analyze the rich set of practices collected throughout the project and to provide guidance for decision and policy makers aiming at promoting a more sustainable use of land. In this light, it suggests a number of recommendations and warnings, bearing in mind that no “right instruments” or “right targets” exist that could prove successful for all European cities and regions.