5 research outputs found
State Estimation Fusion for Linear Microgrids over an Unreliable Network
Microgrids should be continuously monitored in order to maintain suitable voltages over
time. Microgrids are mainly monitored remotely, and their measurement data transmitted through
lossy communication networks are vulnerable to cyberattacks and packet loss. The current study
leverages the idea of data fusion to address this problem. Hence, this paper investigates the effects of
estimation fusion using various machine-learning (ML) regression methods as data fusion methods
by aggregating the distributed Kalman filter (KF)-based state estimates of a linear smart microgrid
in order to achieve more accurate and reliable state estimates. This unreliability in measurements
is because they are received through a lossy communication network that incorporates packet loss
and cyberattacks. In addition to ML regression methods, multi-layer perceptron (MLP) and dependent
ordered weighted averaging (DOWA) operators are also employed for further comparisons.
The results of simulation on the IEEE 4-bus model validate the effectiveness of the employed ML
regression methods through the RMSE, MAE and R-squared indices under the condition of missing
and manipulated measurements. In general, the results obtained by the Random Forest regression
method were more accurate than those of other methods.This research was partially funded by public research projects of Spanish Ministry of
Science and Innovation, references PID2020-118249RB-C22 and PDC2021-121567-C22 - AEI/10.13039/
501100011033, and by the Madrid Government (Comunidad de Madrid-Spain) under the Multiannual
Agreement with UC3M in the line of Excellence of University Professors, reference EPUC3M17
Development of a Customer Churn Model for Banking Industry Based on Hard and Soft Data Fusion
There has been an increase in customer churn over the past few yearsâcustomers decide not to continue purchasing products or services from an organization. Customersâ data lie in two categories: soft and hard. The term âhard dataâ refers to the records generated by various devices and programs, including but not limited to smartphones, computers, sensors, smart meters, fleet management systems, call detail records (CDRs), and consumer bank transaction data. On the other hand, information that is subject to interpretation and viewpoint is known as âsoft data.â Fusing these two types of data leads to better customer behaviour analysis. This paper uses a supervised machine learning algorithm, namely a decision tree (DT), and the change mining method to model hard data. K-means clustering, an unsupervised machine learning algorithm, is also used along with the data preprocessing techniques. This paper also considers the Dempster-Shafer theory and other steps for soft data modelling. By fusing soft and hard data, the churn rate of customers compared with each other can be calculated. Besides, the customersâ banking data are leveraged for data modelling. The results show that the banking industry will gain a more dynamic and efficient customer relationship management system by using this model
Regulation with Guaranteed Convergence Rate for Continuous-Time Systems with Completely Unknown Dynamics in the Presence of Disturbance
This paper presents the design of a novel H â -based control framework for state regulation of continuous-time linear systems with completely unknown dynamics. The proposed method solves the regulation problem with the desired convergence rate and simultaneously seeks to attenuate the adverse effect of disturbance on the system. The H â regulation problem assumes a cost function that considers regulation with a guaranteed rate of convergence as well as disturbance attenuation. The problem is then turned into a two-player zero-sum game optimization problem that can be solved by solving the associated algebraic Riccati equation (ARE), which provides a model-based solution. To solve this problem in a model-free way, a novel integral reinforcement learning (IRL) algorithm is designed to learn the solution online without requiring any prior knowledge of the system dynamics. It is shown that the model-free method (i.e., IRL-based method) provides the same solution as the model-based method (i.e., ARE). The effectiveness of the proposed method is ascertained through simulation examples; it is shown that the proposed method effectively addresses the problem for both stable and unstable systems
Application of smooth fuzzy model in image denoising and edge detection
This article belongs to the Special Issue Soft Methods for Modeling Uncertainty and Imprecision.In this paper, the bounded variation property of fuzzy models with smooth compositions have been studied, and they have been compared with the standard fuzzy composition (e.g., min-max). Moreover, the contribution of the bounded variation of the smooth fuzzy model for the noise removal and edge preservation of the digital images has been investigated. Different simulations on the test images have been employed to verify the results. The performance index related to the detected edges of the smooth fuzzy models in the presence of both Gaussian and Impulse (also known as salt-and-pepper noise) noises of different densities has been found to be higher than the standard well-known fuzzy models (e.g., min-max composition), which demonstrates the efficiency of smooth compositions in comparison to the standard composition.This research was partially funded by public research projects of Spanish Ministry of Science and Innovation, references PID2020-118249RB-C22 and PDC2021-121567-C22-AEI/10.13039/501100011033, and by the Madrid Government (Comunidad de Madrid-Spain) under the Multiannual Agreement with UC3M in the line of Excellence of University Professors, reference EPUC3M17