Wind Power Forecasting Methods Based on Deep Learning: A Survey

Accurate wind power forecasting in wind farm can effectively reduce the enormous impact on grid operation safety when high permeability intermittent power supply is connected to the power grid. Aiming to provide reference strategies for relevant researchers as well as practical applications, this paper attempts to provide the literature investigation and methods analysis of deep learning, enforcement learning and transfer learning in wind speed and wind power forecasting modeling. Usually, wind speed and wind power forecasting around a wind farm requires the calculation of the next moment of the definite state, which is usually achieved based on the state of the atmosphere that encompasses nearby atmospheric pressure, temperature, roughness, and obstacles. As an effective method of high-dimensional feature extraction, deep neural network can theoretically deal with arbitrary nonlinear transformation through proper structural design, such as adding noise to outputs, evolutionary learning used to optimize hidden layer weights, optimize the objective function so as to save information that can improve the output accuracy while filter out the irrelevant or less affected information for forecasting. The establishment of high-precision wind speed and wind power forecasting models is always a challenge due to the randomness, instantaneity and seasonal characteristics

Cooperative Deep Reinforcement Learning for Multiple-Group NB-IoT Networks Optimization

NarrowBand-Internet of Things (NB-IoT) is an emerging cellular-based technology that offers a range of flexible configurations for massive IoT radio access from groups of devices with heterogeneous requirements. A configuration specifies the amount of radio resources allocated to each group of devices for random access and for data transmission. Assuming no knowledge of the traffic statistics, the problem is to determine, in an online fashion at each Transmission Time Interval (TTI), the configurations that maximizes the long-term average number of IoT devices that are able to both access and deliver data. Given the complexity of optimal algorithms, a Cooperative Multi-Agent Deep Neural Network based Q-learning (CMA-DQN) approach is developed, whereby each DQN agent independently control a configuration variable for each group. The DQN agents are cooperatively trained in the same environment based on feedback regarding transmission outcomes. CMA-DQN is seen to considerably outperform conventional heuristic approaches based on load estimation.Comment: Submitted for conference publicatio

A comparative study assessing the wear behaviour of different ceramic die materials during superplastic forming

Superplastic forming (SPF) is an advanced manufacturing process where metallic sheets are heated to their superplastic region to be blow formed within a die set. The process allows for the forming of complex parts but it is typically restricted to low volume and high value products. Ceramic dies are a developing technology in the SPF domain as they offer lower production costs and shorter lead times than conventional metallic dies, thus reducing process costs. Ceramic dies, however, are limited for SPF applications due to their brittle nature. This paper presents a method to assess ceramic die wear which is based on a novel test rig developed at the Advanced Forming Research Centre (AFRC) where SPF die-blank interaction was replicated at laboratory scale. Controllable normal load and twist compression tests on different ceramic materials were carried out with a view to understanding their wear mechanisms and to ultimately identify methods to improve their wear resistance