Energy
Literature Review of the Recent Trends and Applications in various Fuzzy Rule based systems
Varshney, Ayush K., Torra, Vicenç
Fuzzy rule based systems (FRBSs) is a rule-based system which uses linguistic fuzzy variables as antecedents and consequent to represent human understandable knowledge. They have been applied to various applications and areas throughout the soft computing literature. However, FRBSs suffers from many drawbacks such as uncertainty representation, high number of rules, interpretability loss, high computational time for learning etc. To overcome these issues with FRBSs, there exists many extensions of FRBSs. This paper presents an overview and literature review of recent trends on various types and prominent areas of fuzzy systems (FRBSs) namely genetic fuzzy system (GFS), hierarchical fuzzy system (HFS), neuro fuzzy system (NFS), evolving fuzzy system (eFS), FRBSs for big data, FRBSs for imbalanced data, interpretability in FRBSs and FRBSs which use cluster centroids as fuzzy rules. The review is for years 2010-2021. This paper also highlights important contributions, publication statistics and current trends in the field. The paper also addresses several open research areas which need further attention from the FRBSs research community.
Energy Loss Prediction in IoT Energy Services
Yang, Pengwei, Abusafia, Amani, Lakhdari, Abdallah, Bouguettaya, Athman
We propose a novel Energy Loss Prediction(ELP) framework that estimates the energy loss in sharing crowdsourced energy services. Crowdsourcing wireless energy services is a novel and convenient solution to enable the ubiquitous charging of nearby IoT devices. Therefore, capturing the wireless energy sharing loss is essential for the successful deployment of efficient energy service composition techniques. We propose Easeformer, a novel attention-based algorithm to predict the battery levels of IoT devices in a crowdsourced energy sharing environment. The predicted battery levels are used to estimate the energy loss. A set of experiments were conducted to demonstrate the feasibility and effectiveness of the proposed framework. We conducted extensive experiments on real wireless energy datasets to demonstrate that our framework significantly outperforms existing methods.
The Power of Learned Locally Linear Models for Nonlinear Policy Optimization
Pfrommer, Daniel, Simchowitz, Max, Westenbroek, Tyler, Matni, Nikolai, Tu, Stephen
A common pipeline in learning-based control is to iteratively estimate a model of system dynamics, and apply a trajectory optimization algorithm - e.g.~$\mathtt{iLQR}$ - on the learned model to minimize a target cost. This paper conducts a rigorous analysis of a simplified variant of this strategy for general nonlinear systems. We analyze an algorithm which iterates between estimating local linear models of nonlinear system dynamics and performing $\mathtt{iLQR}$-like policy updates. We demonstrate that this algorithm attains sample complexity polynomial in relevant problem parameters, and, by synthesizing locally stabilizing gains, overcomes exponential dependence in problem horizon. Experimental results validate the performance of our algorithm, and compare to natural deep-learning baselines.
Leveraging Deep Learning and Digital Twins to Improve Energy Performance of Buildings
Ni, Zhongjun, Zhang, Chi, Karlsson, Magnus, Gong, Shaofang
Digital transformation in buildings accumulates massive operational data, which calls for smart solutions to utilize these data to improve energy performance. This study has proposed a solution, namely Deep Energy Twin, for integrating deep learning and digital twins to better understand building energy use and identify the potential for improving energy efficiency. Ontology was adopted to create parametric digital twins to provide consistency of data format across different systems in a building. Based on created digital twins and collected data, deep learning methods were used for performing data analytics to identify patterns and provide insights for energy optimization. As a demonstration, a case study was conducted in a public historic building in Norrk\"oping, Sweden, to compare the performance of state-of-the-art deep learning architectures in building energy forecasting.
A hybrid ensemble method with negative correlation learning for regression
Bai, Yun, Tian, Ganglin, Kang, Yanfei, Jia, Suling
Hybrid ensemble, an essential branch of ensembles, has flourished in the regression field, with studies confirming diversity's importance. However, previous ensembles consider diversity in the sub-model training stage, with limited improvement compared to single models. In contrast, this study automatically selects and weights sub-models from a heterogeneous model pool. It solves an optimization problem using an interior-point filtering linear-search algorithm. The objective function innovatively incorporates negative correlation learning as a penalty term, with which a diverse model subset can be selected. The best sub-models from each model class are selected to build the NCL ensemble, which performance is better than the simple average and other state-of-the-art weighting methods. It is also possible to improve the NCL ensemble with a regularization term in the objective function. In practice, it is difficult to conclude the optimal sub-model for a dataset prior due to the model uncertainty. Regardless, our method would achieve comparable accuracy as the potential optimal sub-models. In conclusion, the value of this study lies in its ease of use and effectiveness, allowing the hybrid ensemble to embrace diversity and accuracy.
Faking Fake News for Real Fake News Detection: Propaganda-loaded Training Data Generation
Huang, Kung-Hsiang, McKeown, Kathleen, Nakov, Preslav, Choi, Yejin, Ji, Heng
Despite recent advances in detecting fake news generated by neural models, their results are not readily applicable to effective detection of human-written disinformation. What limits the successful transfer between them is the sizable gap between machine-generated fake news and human-authored ones, including the notable differences in terms of style and underlying intent. With this in mind, we propose a novel framework for generating training examples that are informed by the known styles and strategies of human-authored propaganda. Specifically, we perform self-critical sequence training guided by natural language inference to ensure the validity of the generated articles, while also incorporating propaganda techniques, such as appeal to authority and loaded language. In particular, we create a new training dataset, PropaNews, with 2,256 examples, which we release for future use. Our experimental results show that fake news detectors trained on PropaNews are better at detecting human-written disinformation by 3.62 - 7.69% F1 score on two public datasets.
Federated X-Armed Bandit
Li, Wenjie, Song, Qifan, Honorio, Jean, Lin, Guang
Federated bandit is a newly-developed bandit problem that incorporates federated learning with sequential decision making [McMahan et al., 2017, Shi and Shen, 2021a]. Unlike the traditional bandit models where the exploration-exploitation tradeoff is the only major concern, federated bandit problem also takes account of the modern concerns of data heterogeneity and privacy protection towards trustworthy machine learning. In particular, in the federated learning paradigm, the data available to each client could be drawn from non-i.i.d distributions, making collaborations between the clients necessary to make valid inferences for the aggregated global model. However, due to user privacy concerns and the large communication cost, such collaborations across the clients must be restricted and avoid direct transmissions of the local data. To make correct decisions in the future, the clients have to utilize the limited communications from each other and coordinate exploration and exploitation correspondingly. To the best of our knowledge, existing results of federated bandits, such as Dubey and Pentland [2020], Huang et al. [2021], Shi and Shen [2021a], Shi et al. [2021b], focus on either the case where the number of arms is finite (multi-armed bandit), or the case where the expected reward is a linear function of the chosen arm (linear contextual bandit). However, for problems such as dynamic pricing [Chen and Gallego, 2022] and hyper-parameter optimization [Shang et al., 2019], the available arms are often defined on a domain X with infinite or even uncountable cardinality, and the reward function is usually non-linear with respect to the metric employed by the domain X. These problems challenge the applications of existing federated bandit algorithms to more complicated real-world problems. Two applications (Figure 1) that motivate our study of federated X -armed bandit are given below.
Deep Learning for Anomaly Detection in Log Data: A Survey
Landauer, Max, Onder, Sebastian, Skopik, Florian, Wurzenberger, Markus
Automatic log file analysis enables early detection of relevant incidents such as system failures. In particular, self-learning anomaly detection techniques capture patterns in log data and subsequently report unexpected log event occurrences to system operators without the need to provide or manually model anomalous scenarios in advance. Recently, an increasing number of approaches leveraging deep learning neural networks for this purpose have been presented. These approaches have demonstrated superior detection performance in comparison to conventional machine learning techniques and simultaneously resolve issues with unstable data formats. However, there exist many different architectures for deep learning and it is non-trivial to encode raw and unstructured log data to be analyzed by neural networks. We therefore carry out a systematic literature review that provides an overview of deployed models, data pre-processing mechanisms, anomaly detection techniques, and evaluations. The survey does not quantitatively compare existing approaches but instead aims to help readers understand relevant aspects of different model architectures and emphasizes open issues for future work.
Mastering the exploration-exploitation trade-off in Bayesian Optimization
Gaussian Process based Bayesian Optimization is a well-known sample efficient sequential strategy for globally optimizing black-box, expensive, and multi-extremal functions. The role of the Gaussian Process is to provide a probabilistic approximation of the unknown function, depending on the sequentially collected observations, while an acquisition function drives the choice of the next solution to evaluate, balancing between exploration and exploitation, depending on the current Gaussian Process model. Despite the huge effort of the scientific community in defining effective exploration-exploitation mechanisms, we are still far away from the master acquisition function. This paper merges the most relevant results and insights from both algorithmic and human search strategies to propose a novel acquisition function, mastering the trade-off between explorative and exploitative choices, adaptively. We compare the proposed acquisition function on a number of test functions and against different state-of-the-art ones, which are instead based on prefixed or random scheduling between exploration and exploitation. A Pareto analysis is performed with respect to two (antagonistic) goals: convergence to the optimum and exploration capability. Results empirically prove that the proposed acquisition function is almost always Pareto optimal and also the most balanced trade-off between the two goals.
Perceptive Locomotion through Whole-Body MPC and Optimal Region Selection
Corbères, Thomas, Mastalli, Carlos, Merkt, Wolfgang, Havoutis, Ioannis, Fallon, Maurice, Mansard, Nicolas, Flayols, Thomas, Vijayakumar, Sethu, Tonneau, Steve
Abstract--Real-time synthesis of legged locomotion maneuvers in challenging industrial settings is still an open problem, requiring simultaneous determination of footsteps locations several steps ahead while generating whole-body motions close to the robot's limits. State estimation and perception errors impose the practical constraint of fast re-planning motions in a model predictive control (MPC) framework. We first observe that the computational limitation of perceptive locomotion pipelines lies in the combinatorics of contact surface selection. Re-planning contact locations on selected surfaces can be accomplished at MPC frequencies (50-100 Hz). Then, whole-body motion generation typically follows a reference trajectory for the robot base to facilitate convergence. Our contributions are integrated into a complete framework for perceptive locomotion, validated under diverse terrain conditions, and demonstrated in challenging trials that push the robot's actuation limits, as well as in the ICRA 2023 quadruped challenge simulation. ELIABLE and autonomous locomotion for legged robots in arbitrary environments is a longstanding challenge. A. State of the art The hardware maturity of quadruped robots [1], [2], [3], [4] The mathematical complexity of the legged locomotion motivates the development of a motion synthesis framework problem in arbitrary environments is such that an undesired for applications including inspections in industrial areas [5]. Typically, a contact plan describing the contact handling the issues of contact decision (where should the robot locations is first computed, assumed to be feasible, and provided step?) and Whole-Body Model Predictive Control (WB-MPC) as input to a WB-MPC framework to generate wholebody of the robot (what motion creates the contact?). As a result, the contact decision Each contact decision defines high-dimensional, non-linear must be made using an approximated robot model, under the geometric and dynamic constraints on the WB-MPC that uncertainty that results from imperfect perception and state prevent a trivial decoupling of the two issues: How to prove estimation. The complexity of the approximated model has, that a contact plan is valid without finding a feasible wholebody unsurprisingly, a strong correlation with the versatility and motion to achieve it?