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Deep Learning for Wireless Networked Systems: a joint Estimation-Control-Scheduling Approach

arXiv.org Artificial Intelligence

Wireless networked control system (WNCS) connecting sensors, controllers, and actuators via wireless communications is a key enabling technology for highly scalable and low-cost deployment of control systems in the Industry 4.0 era. Despite the tight interaction of control and communications in WNCSs, most existing works adopt separative design approaches. This is mainly because the co-design of control-communication policies requires large and hybrid state and action spaces, making the optimal problem mathematically intractable and difficult to be solved effectively by classic algorithms. In this paper, we systematically investigate deep learning (DL)-based estimator-control-scheduler co-design for a model-unknown nonlinear WNCS over wireless fading channels. In particular, we propose a co-design framework with the awareness of the sensor's age-of-information (AoI) states and dynamic channel states. We propose a novel deep reinforcement learning (DRL)-based algorithm for controller and scheduler optimization utilizing both model-free and model-based data. An AoI-based importance sampling algorithm that takes into account the data accuracy is proposed for enhancing learning efficiency. We also develop novel schemes for enhancing the stability of joint training. Extensive experiments demonstrate that the proposed joint training algorithm can effectively solve the estimation-control-scheduling co-design problem in various scenarios and provide significant performance gain compared to separative design and some benchmark policies.


Naturally-meaningful and efficient descriptors: machine learning of material properties based on robust one-shot ab initio descriptors

arXiv.org Artificial Intelligence

Establishing a data-driven pipeline for the discovery of novel materials requires the engineering of material features that can be feasibly calculated and can be applied to predict a material's target properties. Here we propose a new class of descriptors for describing crystal structures, which we term Robust One-Shot Ab initio (ROSA) descriptors. ROSA is computationally cheap and is shown to accurately predict a range of material properties. These simple and intuitive class of descriptors are generated from the energetics of a material at a low level of theory using an incomplete ab initio calculation. We demonstrate how the incorporation of ROSA descriptors in ML-based property prediction leads to accurate predictions over a wide range of crystals, amorphized crystals, metal-organic frameworks and molecules. We believe that the low computational cost and ease of use of these descriptors will significantly improve ML-based predictions.



Cross Task Neural Architecture Search for EEG Signal Classifications

arXiv.org Artificial Intelligence

Electroencephalograms (EEGs) are brain dynamics measured outside the brain, which have been widely utilized in non-invasive brain-computer interface applications. Recently, various neural network approaches have been proposed to improve the accuracy of EEG signal recognition. However, these approaches severely rely on manually designed network structures for different tasks which generally are not sharing the same empirical design cross-task-wise. In this paper, we propose a cross-task neural architecture search (CTNAS-EEG) framework for EEG signal recognition, which can automatically design the network structure across tasks and improve the recognition accuracy of EEG signals. Specifically, a compatible search space for cross-task searching and an efficient constrained searching method is proposed to overcome challenges brought by EEG signals. By unifying structure search on different EEG tasks, this work is the first to explore and analyze the searched structure difference cross-task-wise. Moreover, by introducing architecture search, this work is the first to analyze model performance by customizing model structure for each human subject. Detailed experimental results suggest that the proposed CTNAS-EEG could reach state-of-the-art performance on different EEG tasks, such as Motor Imagery (MI) and Emotion recognition. Extensive experiments and detailed analysis are provided as a good reference for follow-up researchers.


Solar Power Time Series Forecasting Utilising Wavelet Coefficients

arXiv.org Artificial Intelligence

Accurate and reliable prediction of Photovoltaic (PV) power output is critical to electricity grid stability and power dispatching capabilities. However, Photovoltaic (PV) power generation is highly volatile and unstable due to different reasons. The Wavelet Transform (WT) has been utilised in time series applications, such as Photovoltaic (PV) power prediction, to model the stochastic volatility and reduce prediction errors. Yet the existing Wavelet Transform (WT) approach has a limitation in terms of time complexity. It requires reconstructing the decomposed components and modelling them separately and thus needs more time for reconstruction, model configuration and training. The aim of this study is to improve the efficiency of applying Wavelet Transform (WT) by proposing a new method that uses a single simplified model. Given a time series and its Wavelet Transform (WT) coefficients, it trains one model with the coefficients as features and the original time series as labels. This eliminates the need for component reconstruction and training numerous models. This work contributes to the day-ahead aggregated solar Photovoltaic (PV) power time series prediction problem by proposing and comprehensively evaluating a new approach of employing WT. The proposed approach is evaluated using 17 months of aggregated solar Photovoltaic (PV) power data from two real-world datasets. The evaluation includes the use of a variety of prediction models, including Linear Regression, Random Forest, Support Vector Regression, and Convolutional Neural Networks. The results indicate that using a coefficients-based strategy can give predictions that are comparable to those obtained using the components-based approach while requiring fewer models and less computational time.


Regularizing Neural Network Training via Identity-wise Discriminative Feature Suppression

arXiv.org Artificial Intelligence

It is well-known that a deep neural network has a strong fitting capability and can easily achieve a low training error even with randomly assigned class labels. When the number of training samples is small, or the class labels are noisy, networks tend to memorize patterns specific to individual instances to minimize the training error. This leads to the issue of overfitting and poor generalisation performance. This paper explores a remedy by suppressing the network's tendency to rely on instance-specific patterns for empirical error minimisation. The proposed method is based on an adversarial training framework. It suppresses features that can be utilized to identify individual instances among samples within each class. This leads to classifiers only using features that are both discriminative across classes and common within each class. We call our method Adversarial Suppression of Identity Features (ASIF), and demonstrate the usefulness of this technique in boosting generalisation accuracy when faced with small datasets or noisy labels. Our source code is available.


Boosting Exploration in Actor-Critic Algorithms by Incentivizing Plausible Novel States

arXiv.org Artificial Intelligence

Actor-critic (AC) algorithms are a class of model-free deep reinforcement learning algorithms, which have proven their efficacy in diverse domains, especially in solving continuous control problems. Improvement of exploration (action entropy) and exploitation (expected return) using more efficient samples is a critical issue in AC algorithms. A basic strategy of a learning algorithm is to facilitate indiscriminately exploring all of the environment state space, as well as to encourage exploring rarely visited states rather than frequently visited one. Under this strategy, we propose a new method to boost exploration through an intrinsic reward, based on measurement of a state's novelty and the associated benefit of exploring the state (with regards to policy optimization), altogether called plausible novelty. With incentivized exploration of plausible novel states, an AC algorithm is able to improve its sample efficiency and hence training performance. The new method is verified by extensive simulations of continuous control tasks of MuJoCo environments on a variety of prominent off-policy AC algorithms.


Integrating Conventional Headway Control with Reinforcement Learning to Avoid Bus Bunching

arXiv.org Artificial Intelligence

Bus bunching is a natural-occurring phenomenon that undermines the efficiency and stability of the public transportation system. The mainstream solutions control the bus to intentionally stay longer at certain stations. Existing control methods include conventional methods that provide a formula to calculate the control time and reinforcement learning (RL) methods that determine the control policy through repeated interactions with the system. In this paper, we propose an integrated proximal policy optimization model with dual-headway (IPPO-DH). IPPO-DH integrates the conventional headway control with reinforcement learning, so that it acquires the advantages of both algorithms -- it is more efficient in normal environments and more stable in harsh ones. To demonstrate such an advantage, we design a bus simulation environment and compare IPPO-DH with RL and several conventional methods. The results show that the proposed model maintains the application value of the conventional method by avoiding the instability of the RL method in certain environments, and improves the efficiency compared with the conventional control, shedding new light on real-world bus transit system optimization.


Design of Economical Fuzzy Logic Controller for Washing Machine

arXiv.org Artificial Intelligence

Things are becoming more advanced as technology advances, and machines now perform the majority of the manual work. The most often used home appliance is the washing machine for cloths. Modification and research in this field is essential since it pertains to the amount of time, water, and electricity required for washing. In this work, a Fuzzy Logic Controller has been developed for smart washing machines. The objective of this paper is to optimize the consumption of electricity, water, and detergent for washing machines. The type of dirt, volume of clothes, and type of cloth play a vital role in saving water, electricity, and detergent. However, none of the work on the Fuzzy Logic Controller provided a design procedure endowed with the specified inputs and outputs implemented in Python. In this paper, we used the Mamdani approach and created an algorithm based on multi-input multi-output. The algorithm is implemented in Python. The results of this simulation show that the washing machine provides better execution at a low computation cost.


Food Delivery Drone Crashes Into Power Lines, Leaving Thousands Without Electricity

International Business Times

Thousands of residents were left without electricity after a food delivery drone crashed into power lines in Australia. The power company, Energex, had to shut down the network after a crew was called to the incident Thursday in Browns Plains, south of Brisbane. While Energex was able to restore electricity for about 2,000 customers within 45 minutes, 300 remained without power for at least three hours, due to being in close vicinity of the drone crash, ABC News said Friday. Energex spokesman Danny Donald told ABC Radio they had never seen delivery drones hitting the network. "We've never seen these delivery drones hit the network. "This is the first time that I've seen it happen.