Accurate energy consumption forecasting is critical for optimizing energy usage, lowering operational costs, and encouraging sustainability in smart buildings. Machine learning (ML) has developed as an effective method for energy forecasting, using sensor data to anticipate consumption trends and increase efficiency. However, due to regulations such as GDPR and growing privacy concerns, sharing sensitive energy data with third parties is often prohibited, providing issues for traditional centralized ML techniques. Federated Learning (FL) provides a feasible alternative by allowing for decentralized model training across several buildings without explicitly exchanging raw data. This privacy-preserving strategy enables organizations to jointly train reliable models while retaining data sovereignty. Our experimental results demonstrate that by using the CU-BEMS dataset, both FL and centralized forecasting models perform similarly, with an R2score of ≈87%. Furthermore, FL decreases bandwidth use by limiting data transfers, making it a scalable and economical energy management solution for smart buildings. These findings demonstrate FL’s ability to ensure safe, data-driven decision-making for sustainable energy utilization.

Context: Detecting fatigue in drivers has become increasingly important for safe driving, especially with the use of more smart devices and Internet-connected vehicles. While sharing data between vehicles can enhance fatigue detection systems, privacy concerns pose significant barriers to this sharing process. We propose a Federated Learning (FL) approach for monitoring fatigue-driven behavior to address these challenges. However, there is a concern that the drivers' private information might be leaked in the FL system. In this paper, we introduce PRIV-DRIVE, a novel approach for privacy-enhanced fatigue detection applications. Our method integrates Paillier homo-morphic encryption (PHE) with a top-k parameter selection technique, bolstering privacy and confidentiality in federated fatigue detection systems. This approach reduces communication and computation overhead while ensuring model accuracy. To the best of our knowledge, this is the first paper to implement PHE in FL setups for fatigue detection applications. We ran several experiments and evaluated the PRIV-DRIVE method. The results show substantial efficiency gains with different HE key sizes, reducing computation time by up to 96% and communication traffic by up to 95%. Importantly, these improvements have minimal impact on accuracy, effectively meeting the requirements of fatigue detection applications.

Federated learning (FL) as a novel paradigm in Artificial Intelligence (AI), ensures enhanced privacy by eliminating data centralization and brings learning directly to the edge of the user's device. Nevertheless, new privacy issues have been raised particularly during training and the exchange of parameters between servers and clients. While several privacy-preserving FL solutions have been developed to mitigate potential breaches in FL architectures, their integration poses its own set of challenges. Incorporating these privacy-preserving mechanisms into FL at the edge computing level can increase both communication and computational overheads, which may, in turn, compromise data utility and learning performance metrics. This paper provides a systematic literature review on essential methods and metrics to support the most appropriate trade-offs between FL privacy and other performance-related application requirements such as accuracy, loss, convergence time, utility, communication, and computation overhead. We aim to provide an extensive overview of recent privacy-preserving mechanisms in FL used across various applications, placing a particular focus on quantitative privacy assessment approaches in FL and the necessity of achieving a balance between privacy and the other requirements of real-world FL applications. This review collects, classifies, and discusses relevant papers in a structured manner, emphasizing challenges, open issues, and promising research directions.

In smart electric grid systems, various sensors and Internet of Things (IoT) devices are used to collect electrical data at substations. In a traditional system, a multitude of energy-related data from substations needs to be migrated to central storage, such as Cloud or edge devices, for knowledge extraction that might impose severe data misuse, data manipulation, or privacy leakage. This motivates to propose anomaly detection system to detect threats and Federated Learning to resolve the issues of data silos and privacy of data. In this article, we present a framework to identify anomalies in industrial data that are gathered from the remote terminal devices deployed at the substations in the smart electric grid system. The anomaly detection system is based on Long Short-Term Memory (LSTM) and autoencoders that employs Mean Standard Deviation (MSD) and Median Absolute Deviation (MAD) approaches for detecting anomalies. We deploy Federated Learning (FL) to preserve the privacy of the data generated by the substations. FL enables energy providers to train shared AI models cooperatively without disclosing the data to the server. In order to further enhance the security and privacy properties of the proposed framework, we implemented homomorphic encryption based on the Paillier algorithm for preserving data privacy. The proposed security model performs better with MSD approach using HE-128 bit key providing 97% F1-score and 98% accuracy for K=5 with low computation overhead as compared with HE-256 bit key.

Context: Federated Learning is an approach to distributed machine learning that enables collaborative model training on end devices. FL enhances privacy as devices only share local model parameters instead of raw data with a central server. However, the central server or eavesdroppers could extract sensitive information from these shared parameters. This issue is crucial in applications like speech emotion recognition (SER) that deal with personal voice data. To address this, we propose Optimized Paillier Homomorphic Encryption (OPHE) for SER applications in FL. Paillier homomorphic encryption enables computations on ciphertext, preserving privacy but with high computation and communication overhead. The proposed OPHE method can reduce this overhead by combing Paillier homomorphic encryption with pruning. So, we employ OPHE in one of the use cases of a large research project (DAIS) funded by the European Commission using a public SER dataset.

Context: Speech Emotion Recognition (SER) is a valuable technology that identifies human emotions from spoken language, enabling the development of context-aware and personalized intelligent systems.To protect user privacy, Federated Learning (FL) has been introduced, enabling local training of models on user devices.However, FL raises concerns about the potential exposure of sensitive information from local model parameters, which is especially critical in applications like SER that involve personal voice data.Local Differential Privacy (LDP) has prevented privacy leaks in image and video data.However, it encounters notable accuracy degradation when applied to speech data, especially in the presence of high noise levels.In this paper, we propose an approach called LDP-FL with CSS, which combines LDP with a novel client selection strategy (CSS).By leveraging CSS, we aim to improve the representatives of updates and mitigate the adverse effects of noise on SER accuracy while ensuring client privacy through LDP.Furthermore, we conducted model inversion attacks to evaluate the robustness of LDP-FL in preserving privacy.These attacks involved an adversary attempting to reconstruct individuals' voice samples using the output labels provided by the SER model.The evaluation results reveal that LDP-FL with CSS achieved an accuracy of 65-70%, which is 4% lower than the initial SER model accuracy.Furthermore, LDP-FL demonstrated exceptional resilience against model inversion attacks, outperforming the non-LDP method by a factor of 10.Overall, our analysis emphasizes the importance of achieving a balance between privacy and accuracy in accordance with the requirements of the SER application.

Deep model compression has been studied widely, and state-of-the-art methods can now achieve high compression ratios with minimum accuracy loss. Recent advances in adversarial attacks reveal the inherent vulnerability of deep neural networks to slightly perturbed images called adversarial examples. Since then, extensive efforts have been performed to enhance deep networks' robustness via specialized loss functions and learning algorithms. Previous works suggest that network size and robustness against adversarial examples contradict on most occasions. In this paper, we investigate how to optimize compactness and robustness to adversarial attacks of neural network architectures while maintaining the accuracy using multi-objective neural architecture search. We propose the use of previously generated adversarial examples as an objective to evaluate the robustness of our models in addition to the number of floating-point operations to assess model complexity i.e. compactness. Experiments on some recent neural architecture search algorithms show that due to their limited search space they fail to find robust and compact architectures. By creating a novel neural architecture search (RoCo-NAS), we were able to evolve an architecture that is up to 7% more accurate against adversarial samples than its more complex architecture counterpart. Thus, the results show inherently robust architectures regardless of their size. This opens up a new range of possibilities for the exploration and design of deep neural networks using automatic architecture search.

Long Short-Term Memory (LSTM) is one of the most popular and effective Recurrent Neural Network (RNN) models used for sequence learning in applications such as ECG signal classification. Complex LSTMs could hardly be deployed on resource-limited bio-medical wearable devices due to the huge amount of computations and memory requirements. Binary LSTMs are introduced to cope with this problem. However, naive binarization leads to significant accuracy loss in ECG classification. In this paper, we propose an efficient LSTM cell along with a novel hardware architecture for ECG classification. By deploying 5-level binarized inputs and just 1- level binarization for weights, output, and in-memory cell activations, the delay of one LSTM cell operation is reduced 50x with about 0.004% accuracy loss in comparison with full precision design of ECG classification.

Recurrent Neural Networks (RNN) are widely used for learning sequences in applications such as EEG classification. Complex RNNs could be hardly deployed on wearable devices due to their computation and memory-intensive processing patterns. Generally, reduction in precision leads much more efficiency and binarized RNNs are introduced as energy-efficient solutions. However, naive binarization methods lead to significant accuracy loss in EEG classification. In this paper, we propose a multi-level binarized LSTM, which significantly reduces computations whereas ensuring an accuracy pretty close to the full precision LSTM. Our method reduces the delay of the 3-bit LSTM cell operation 47× with less than 0.01% accuracy loss.

Long Short-Term Memory (LSTM) is widely used in various sequential applications. Complex LSTMs could be hardly deployed on wearable and resourced-limited devices due to the huge amount of computations and memory requirements. Binary LSTMs are introduced to cope with this problem, however, they lead to significant accuracy loss in some applications such as EEG classification which is essential to be deployed in wearable devices. In this paper, we propose an efficient multi-level binarized LSTM which has significantly reduced computations whereas ensuring an accuracy pretty close to full precision LSTM. By deploying 5-level binarized weights and inputs, our method reduces area and delay of MAC operation about $31\times and 27\times$ in 65nm technology, respectively with less than 0.01% accuracy loss. In contrast to many compute-intensive deep-learning approaches, the proposed algorithm is lightweight, and therefore, brings performance efficiency with accurate LSTM-based EEG classification to realtime wearable devices.

Task mapping exploration plays an important role in the high performance achieved by heterogeneous multi-processor system-on-chip (MPSoC) platforms. The dynamic of application workloads in modern MPSoC-based embedded systems are consistently growing. Nowadays, the execution of different applications is done concurrently and these applications compete for resources in such systems. This paper presents a novel run-time mapping algorithm for multimedia applications. The objective of application mapping is to minimize execution time in a predefined budget of energy consumption. This algorithm is divided to two phases: design-time and run-time. During design-time, application clustering is combined with design space exploration, then a set of rules for mapping is extracted by using Association Rule Mining techniques, and after that, during run-time, feature extraction and application classification is performed based on the rule sets. The evaluation of the proposed algorithm is done by using a heterogeneous MPSoC system with several applications that have different communication and computation behaviors. The experimental results revealed that during run-time, applications were correctly classified by the proposed algorithm and the best resources selected for mapping accurately. The results clearly showcase the proposed algorithm's effectiveness.

Electronic System level design has an important role in the multi-processor embedded system on chip design. Two important steps in this process are evaluation of a single design configuration and design space exploration. In the first part of design process, high-level simple analytical models for application mapping and evaluation are used and modified aiming at accelerating the evaluation of a single design configuration. Using the analytical model the design space is pruned and explored at high speed with low accuracy. In the second part of the design process, two Multi Objective Optimization Algorithms based on Particle Swarm Optimization and Simulated Annealing have been proposed to perform design space exploration of the pruned design space with higher accuracy taking advantages of low-level architectural simulation engines. The results obtained by proposed algorithms will provide the designer more accurate solutions within an acceptable time. Considering the MJPEG application as the case study, each of these methods produces a set of near-optimal points. Simulation results show that the proposed methods can lead to near-optimal design configurations with acceptable accuracy in reasonable time.